Mac OS X Dev Setup

TODO:

• Postman and Postman Interceptor
• GitHub Desktop
• WagonHQ
• git autocomplete curl -O https://raw.githubusercontent.com/git/git/master/contrib/completion/git-completion.bash https://git-scm.com/book/en/v1/Git-Basics-Tips-and-Tricks

This document describes how I set up my developer environment on a new MacBook or iMac. We will set up popular programming languages (for example Node (JavaScript), Python, and Ruby). You may not need all of them for your projects, although I recommend having the three first three set up as they always come in handy.

The document assumes you are new to Mac, but can also be useful if you are reinstalling a system and need some reminder. The steps below were tested on OS X El Capitan (10.11).

(Note: This is the second version of this guide. If you are looking for the first version written for OS X Mountain Lion, see 1.0)

If you have any comments or suggestions, feel free to give me a shout on Twitter!

• System update
• System preferences
• Security
• Google Chrome
• iTerm2
• Homebrew
• Beautiful terminal
• iTerm2
• Git
• Sublime Text
• Vim
• Python
• Node.js
• Ruby
• Heroku
• PostgreSQL
• Redis
• MongoDB
• Elasticsearch
• Projects folder
• Apps

System update

First thing you need to do, on any OS actually, is update the system! For that: Apple Icon > About This Mac then Software Update....

System preferences

If this is a new computer, there are a couple tweaks I like to make to the System Preferences. Feel free to follow these, or to ignore them, depending on your personal preferences.

In Apple Icon > System Preferences:

• Trackpad > Tap to click
• Keyboard > Key Repeat > Fast (all the way to the right)
• Keyboard > Delay Until Repeat > Short (all the way to the right)
• Dock > Automatically hide and show the Dock

Security

I recommend checking that basic security settings are enabled. You will be happy to have done so if ever your Mac is lost or stolen.

In Apple Icon > System Preferences:

• Users & Groups: If you haven't already set a password for your user during the initial set up, you should do so now
• Security & Privacy > General: Require password immediately after sleep or screen saver begins (you can keep a grace period of a couple minutes if you prefer, but I like to know that my computer locks as soon as I close it)
• Security & Privacy > FileVault: Make sure FileVault disk encryption is enabled
• iCloud: If you haven't already done so during set up, enable Find My Mac

Google Chrome

Install your favorite browser, mine happens to be Chrome.

Download from www.google.com/chrome. Open the .dmg file once it's done downloading (this will mount the disk image), and drag and drop the Google Chrome app into the Applications folder (on the Mac, most applications are installed this way). When done, you can unmount the disk in Finder (the small "eject" icon next to the disk under Devices).

iTerm2

Since we're going to be spending a lot of time in the command-line, let's install a better terminal than the default one. Download and install iTerm2.

In Finder, drag and drop the iTerm Application file into the Applications folder.

You can now launch iTerm, through the Launchpad for instance.

Let's just quickly change some preferences. In iTerm2 > Preferences..., under the tab General, uncheck Confirm closing multiple sessions and Confirm "Quit iTerm2 (Cmd+Q)" command under the section Closing.

In the tab Profiles, create a new one with the "+" icon, and rename it to your first name for example. Then, select Other Actions... > Set as Default. Under the section General set Working Directory to be Reuse previous session's directory. Finally, under the section Window, change the size to something better, like Columns: 125 and Rows: 35.

When done, hit the red "X" in the upper left (saving is automatic in OS X preference panes). Close the window and open a new one to see the size change.

Homebrew

Package managers make it so much easier to install and update applications (for Operating Systems) or libraries (for programming languages). The most popular one for OS X is Homebrew.

Install

An important dependency before Homebrew can work is the Command Line Developer Tools for Xcode. These include compilers that will allow you to build things from source. You can install them directly from the terminal with:

xcode-select --install

Once that is done, we can install Hombrew by copy-pasting the installation command from the [Homebrew homepage](Homebrew inside the terminal.

Follow the steps on the screen. You will be prompted for your user password so Homebrew can set appropriate permissions.

Once installation is complete, you can run the following command to make sure everything works:

brew doctor

Usage

To install a package (or Formula in Homebrew vocabulary) simply type:

brew install <formula>

To update Homebrew's directory of formulae, run:

brew update

Note: I've seen that command fail sometimes because of a bug. If that ever happens, run the following (when you have Git installed):

cd /usr/local
git fetch origin
git reset --hard origin/master

To see if any of your packages need to be updated:

brew outdated

To update a package:

brew upgrade <formula>

Homebrew keeps older versions of packages installed, in case you want to roll back. That rarely is necessary, so you can do some cleanup to get rid of those old versions:

brew cleanup

To see what you have installed (with their version numbers):

brew list --versions

Homebrew Services

A nice extension to Homebrew is Homebrew Services. It will automatically launch things like databases when your computer starts, so you don't have to do it manually every time.

To install it, simply run:

brew tap homebrew/services

After installing a service (for example a database), it should automatically add itself to Hombrew Services. If not, you can add it manually with:

brew services <formula>

Start a service with:

brew services start <formula>

At anytime you can view which services are running with:

brew services list

Beautiful terminal

Since we spend so much time in the terminal, we should try to make it a more pleasant and colorful place. What follows might seem like a lot of work, but trust me, it'll make the development experience so much better.

First let's add some color. There are many great color schemes out there, but if you don't know where to start you can try Oceanic Next. Download the iTerm presets for the theme by running:

cd ~/Downloads
curl -O https://raw.githubusercontent.com/mhartington/oceanic-next-iterm/master/Oceanic-Next.itermcolors

Then, in iTerm2 Preferences, under Profiles and Colors, go to Load Presets... > Import..., find and open the Oceanic-Next.itermcolors file we just downloaded. Go back to Load Presets... and select Oceanic Next to activate it. Voila!

Not a lot of colors yet. We need to tweak a little bit our Unix user's profile for that. This is done (on OS X and Linux), in the ~/.bash_profile text file (~ stands for the user's home directory).

We'll come back to the details of that later, but for now, just download the files .bash_profile, .bash_prompt, .aliases attached to this document into your home directory (.bash_profile is the one that gets loaded, I've set it up to call the others):

cd ~
curl -O https://raw.githubusercontent.com/nicolashery/mac-dev-setup/master/.bash_profile
curl -O https://raw.githubusercontent.com/nicolashery/mac-dev-setup/master/.bash_prompt
curl -O https://raw.githubusercontent.com/nicolashery/mac-dev-setup/master/.aliases

With that, open a new terminal tab (Cmd+T) and see the change! Try the list commands: ls, ls -lh (aliased to ll), ls -lha (aliased to la).

Now we have a terminal we can work with!

(Thanks to Mathias Bynens for his awesome dotfiles.)

Git

Mac OS X comes with a pre-installed version of Git, but we'll install our own through Homebrew to allow easy upgrades and not interfere with the system version. To do so, simply run:

brew update
brew install git

When done, to test that it installed fine you can run:

which git

The output should be /usr/local/bin/git.

Let's set up some basic configuration. Download the .gitconfig file to your home directory:

cd ~
curl -O https://raw.githubusercontent.com/nicolashery/mac-dev-setup/master/.gitconfig

It will add some color to the status, branch, and diff Git commands, as well as a couple aliases. Feel free to take a look at the contents of the file, and add to it to your liking.

Next, we'll define your Git user (should be the same name and email you use for GitHub and Heroku):

git config --global user.name "Your Name Here"
git config --global user.email "[email protected]"

They will get added to your .gitconfig file.

On a Mac, it is important to remember to add .DS_Store (a hidden OS X system file that's put in folders) to your project .gitignore files. You can take a look at this repository's .gitignore file for inspiration. You can also set it up in a global .gitignore file by cloning it into your home directory (but you'll want to make sure any collaborators also do it):

cd ~
curl -O https://raw.githubusercontent.com/nicolashery/mac-dev-setup/master/.gitignore

Sublime Text

With the terminal, the text editor is a developer's most important tool. Everyone has their preferences, but if you're just getting started and looking for something simple that works, Sublime Text is a pretty good option.

Go ahead and download it. Open the .dmg file, drag-and-drop in the Applications folder, you know the drill now. Launch the application.

Note: At this point I'm going to create a shortcut on the OS X Dock for both for Sublime Text and iTerm. To do so, right-click on the running application and select Options > Keep in Dock.

Sublime Text is not free, but I think it has an unlimited "evaluation period". Anyhow, we're going to be using it so much that even the seemingly expensive $70 price tag is worth every penny. If you can afford it, I suggest you support this awesome tool. :)

Just like the terminal, let's configure our editor a little. Go to Sublime Text > Preferences > Settings - User and paste the following in the file that just opened:

{
  "font_size": 13,
  "rulers":
  [
      79
  ],
  "highlight_line": true,
  "bold_folder_labels": true,
  "highlight_modified_tabs": true,
  "tab_size": 2,
  "translate_tabs_to_spaces": true,
  "word_wrap": false,
  "indent_to_bracket": true,
  "trim_trailing_white_space_on_save": true,
  "ensure_newline_at_eof_on_save": true
}

Feel free to tweak these (like the font size) to your preference. When done, save the file and close it.

I use tab size 2 for everything except Python and Markdown files, where I use tab size 4. If you have a Python and Markdown file handy (or create dummy ones with $ touch dummy.py), for each one, open it and go to Sublime Text > Preferences > Settings - More > Syntax Specific - User to paste in:

{
  "tab_size": 4
}

Sublime Text is very extensible. To customize it further, we are going to install the Sublime Package Control. Copy the snippet for Sublime Text 3 from the installation page, and back in your editor open the console with Ctrl+` (back tick), paste the snippet, and hit Enter.

Once installation is complete, restart Sublime Text (Note: on the Mac, closing all windows doesn't close the application, you need to hit Cmd+Q).

To install a new package, open the command list with Cmd+Shift+P, type "install", and select Package Control: Install Package.

Let's use this to customize the color of our editor. I'm going to change two things: the Theme (which is how the tabs, the file explorer on the left, etc. look) and the Color Scheme (the colors of the code). Again, feel free to pick different ones, or stick with the default.

A popular Theme is the Soda Theme. To install it, open Package Control's installation list as described above and type "soda". Select Theme - Soda from the list.

After the installation is complete, go to Sublime Text > Preferences > Settings - User and add the following lines:

{
  "theme": "Soda Dark 3.sublime-theme",
  "soda_classic_tabs": true
}

For the Color Scheme, you can pick one from those that ship with Sublime Text by going to Sublime Text > Preferences > Color Scheme. Or you can install one using Package Control. Let's do that and install Oceanic Next to match the color scheme of our terminal. Hit Cmd+Shift+P, select Package Control: Install Package, search for "oceanic next", and select Oceanic Next Color Scheme.

Activate the Color Scheme by adding this line to Sublime Text > Preferences > Settings - User:

{
  "color_scheme": "Packages/Oceanic Next Color Scheme/Oceanic Next.tmTheme"
}

Sublime Text already supports syntax highlighting for a lot of languages. You can always install more for other languages you work with using Package Control.

Let's create a command line shortcut so we can launch Sublime Text from the terminal:

cd ~
mkdir bin
ln -s "/Applications/Sublime Text.app/Contents/SharedSupport/bin/subl" ~/bin/subl

Now I can open a file with $ subl myfile.py or start a new project in the current directory with $ subl .. Pretty cool.

Vim

Although Sublime Text will be our main editor, it is a good idea to learn some very basic usage of Vim. It is a very popular text editor inside the terminal, and is usually pre-installed on any Unix system.

For example, when you run a Git commit, it will open Vim to allow you to type the commit message.

I suggest you read a tutorial on Vim. Grasping the concept of the two "modes" of the editor, Insert (by pressing i) and Normal (by pressing Esc to exit Insert mode), will be the part that feels most unnatural. Also, it is good to know that typing :wq when in Normal mode will save and exit. After that, it's just remembering a few important keys.

Vim's default settings aren't great, and you could spend a lot of time tweaking your configuration (the .vimrc file). But if you're like me and just use Vim occasionally, you'll be happy to know that Tim Pope has put together some sensible defaults to quickly get started.

First, install pathogen.vim by running:

mkdir -p ~/.vim/autoload ~/.vim/bundle && \
curl -LSso ~/.vim/autoload/pathogen.vim https://tpo.pe/pathogen.vim

Then create a file ~/.vimrc (you can use $ subl ~/.vimrc), and paste in the following:

execute pathogen#infect()
syntax on
filetype plugin indent on

And finally, install the Vim "sensible defaults" by running:

cd ~/.vim/bundle
git clone git://github.com/tpope/vim-sensible.git

With that, Vim will look a lot better next time you open it!

Python

OS X, like Linux, ships with Python already installed. But you don't want to mess with the system Python (some system tools rely on it, etc.), so we'll install our own version using pyenv. This will also allow us to manage multiple versions of Python (ex: 2.7 and 3) should we need to.

Install pyenv via Homebrew by running:

brew install pyenv

When finished, you should see instructions to add something to your profile. Open your .bash_profile in the home directory (you can use $ subl ~/.bash_profile), and add the following line:

if which pyenv > /dev/null; then eval "$(pyenv init -)"; fi

Save the file and reload it with:

source ~/.bash_profile

We can now list all available Python versions by running:

pyenv install --list

Look for the latest 2.7.x version (or 3.x), and install it:

pyenv install 2.7.13 # the latest version might be different

List the Python versions you have locally with:

pyenv versions

The start (*) should indicate we are still using the system version. We should set the one we installed to be the default:

pyenv global 2.7.13

You should now see that version when running:

python --version

For more information, see the pyenv commands documentation.

pip

pip was also installed by pyenv. It is the package manager for Python.

Here are a couple Pip commands to get you started. To install a Python package:

pip install <package>

To upgrade a package:

pip install --upgrade <package>

To see what's installed:

pip freeze

To uninstall a package:

pip uninstall <package>

virtualenv

virtualenv is a tool that creates an isolated Python environment for each of your projects. For a particular project, instead of installing required packages globally, it is best to install them in an isolated folder, that will be managed by virtualenv.

The advantage is that different projects might require different versions of packages, and it would be hard to manage that if you install packages globally. It also allows you to keep your global site-packages folder clean, containing only big packages that you always need (for example Numpy and Scipy).

Instead of installing and using virtualenv directly, we'll use the dedicated pyenv plugin pyenv-virtualenv which will make things a bit easier for us. Install it via Homebrew:

brew install pyenv-virtualenv

After installation, add the following line to your .bash_profile;

if which pyenv-virtualenv-init > /dev/null; then eval "$(pyenv virtualenv-init -)"; fi

And reload it with:

source ~/.bash_profile

Now, let's say you have a project called myproject. You can set up virtualenv for that project and the Python version it uses (for example 2.7.13):

pyenv virtualenv 2.7.13 myproject

See the list of virtualenvs you created with:

pyenv virtualenvs

To use your project's virtualenv, you need to activate it first (in every terminal where you are working on your project):

pyenv activate myproject

You should see a (myproject) appear at the baeginning of your terminal prompt indicating that you are working inside the virtualenv. Now when you install something:

pip install <package>

It will get installed in that virtualenv's folder, and not conflict with other projects.

IPython

IPython is an awesome project which provides a much better Python shell than the one you get from running $ python in the command-line. It has many cool functions (running Unix commands from the Python shell, easy copy & paste, creating Matplotlib charts in-line, etc.) and I'll let you refer to the documentation to discover them.

Before we install IPython, we'll need to get some dependencies. Run the following:

$ brew update # Always good to do
$ brew install zeromq # Necessary for pyzmq
$ brew install pyqt # Necessary for the qtconsole

It may take a few minutes to build these.

Once it's done, we can install IPython with all the available options:

$ pip install ipython[zmq,qtconsole,notebook,test]

You can launch IPython from the command line with $ ipython, but what's more interesting is to use its QT Console. Launch the QT Console by running:

$ ipython qtconsole

You can also customize the font it uses:

$ ipython qtconsole --ConsoleWidget.font_family="Consolas" --ConsoleWidget.font_size=13

And since I'm lazy and I don't want to type or copy & paste that all the time, I'm going to create an alias for it. Create a .extra text file in your home directory with $ subl ~/.extra (I've set up .bash_profile to load .extra), and add the following line:

alias ipy='ipython qtconsole --ConsoleWidget.font_family="Consolas" --ConsoleWidget.font_size=13'

Open a fresh terminal. Now when you run $ ipy, it will launch the QT Console with your configured options.

To use the in-line Matplotlib functionality (nice for scientific computing), run $ ipy --pylab=inline.

Numpy and Scipy

The Numpy and Scipy scientific libraries for Python are always a little tricky to install from source because they have all these dependencies they need to build correctly. Luckily for us, Samuel John has put together some Homebrew formulae to make it easier to install these Python libraries.

First, grab the special formulae (which are not part of Homebrew core):

$ brew tap samueljohn/python
$ brew tap homebrew/science

Then, install the gfortran dependency (now in gcc) which we will need to build the libraries:

$ brew install gcc

Finally, you can install Numpy and Scipy with:

$ brew install numpy
$ brew install scipy

(It may take a few minutes to build.)

Node.js

The recommended way to install Node.js is to use nvm (Node Version Manager) which allows you to manage multiple versions of Node.js on the same machine.

Install nvm by copy-pasting the install script command into your terminal.

Once that is done, open a new terminal and verify that it was installed correctly by running:

command -v nvm

Install the latest stable version of Node.js with:

nvm install node

It will also set this version as your default version. You can install another specific version, for example Node 4, with:

nvm install 4

And switch between versions by using:

nvm use 4
nvm use default

Installing Node also installs the npm package manager.

Npm usage

To install a package:

npm install <package> # Install locally
npm install -g <package> # Install globally

To install a package and save it in your project's package.json file:

npm install <package> --save

To see what's installed:

npm list # Local
npm list -g # Global

To find outdated packages (locally or globally):

npm outdated [-g]

To upgrade all or a particular package:

npm update [<package>]

To uninstall a package:

npm uninstall <package>

ESLint

ESLint is a JavaScript developer's best friend. With Sublime Text, you can get real-time linting right inside the editor thanks to the SublimeLinter package.

First install eslint_d globally via npm:

npm install -g eslint_d

Then install the following packages through Sublime Text's Package Control:

• SublimeLinter
• SublimeLinter-contrib-eslint_d

Ruby

Like Python, Ruby is already installed on Unix systems. But we don't want to mess around with that installation. More importantly, we want to be able to use the latest version of Ruby.

Install

When installing Ruby, best practice is to use RVM (Ruby Version Manager) which allows you to manage multiple versions of Ruby on the same machine. Installing RVM, as well as the latest version of Ruby, is very easy. Just run:

curl -sSL https://get.rvm.io | bash -s stable --ruby

When it is done, both RVM and a fresh version of Ruby are installed.

Open a new terminal and run:

type rvm | head -1

You should get the output rvm is a function.

Usage

The following command will show you which versions of Ruby you have installed:

rvm list

The one that was just installed, Ruby 2, should be set as default. When managing multiple versions, you switch between them with:

rvm use system # Switch back to system install (ex: 2.0)
rvm use 2.3 --default # Switch to 2.3 and sets it as default

Run the following to make sure the version you want is being used:

which ruby
ruby --version

You can install another version with:

rvm install 2.2

To update RVM itself, use:

rvm get stable

RubyGems, the Ruby package manager, was also installed:

which gem

Update to its latest version with:

gem update --system

To install a "gem" (Ruby package), run:

gem install <gemname>

To install without generating the documentation for each gem (faster):

gem install <gemname> --no-document

To see what gems you have installed:

gem list

To check if any installed gems are outdated:

gem outdated

To update all gems or a particular gem:

gem update [<gemname>]

RubyGems keeps old versions of gems, so feel free to do come cleaning after updating:

gem cleanup

Heroku

Heroku, if you're not already familiar with it, is a Platform-as-a-Service (PaaS) that makes it really easy to deploy your apps online. There are other similar solutions out there, but Heroku was among the first and is currently the most popular. Not only does it make a developer's life easier, but I find that having Heroku deployment in mind when building an app forces you to follow modern app development best practices.

Assuming that you have an account (sign up if you don't), let's install the Heroku CLI. Heroku offers a Mac OS X installer, the Heroku Toolbelt, that includes the client. But for these kind of tools, I prefer using Homebrew. It allows us to keep better track of what we have installed. Luckily for us, Homebrew includes a heroku-toolbelt formula:

brew install heroku-toolbelt

Login to your Heroku account using your email and password:

heroku login

Once logged-in, you're ready to deploy apps! Heroku has a great Getting Started guides for different languages, so I'll let you refer to that. Heroku uses Git to push code for deployment, so make sure your app is under Git version control. A quick cheat sheet (if you've used Heroku before):

cd myapp/
heroku create myapp
git push heroku master
heroku ps
heroku logs -t

The Heroku Dev Center is full of great resources, so be sure to check it out!

PostgreSQL

PostgreSQL is a popular relational database, and Heroku has first-class support for it.

Install PostgreSQL using Homebrew:

brew update # Always good to do
brew install postgresql

It will automatically add itself to Homebrew Services. Start it with:

brew services start postgresql

If you reboot your machine, PostgreSQL will be restarted at login.

Redis

Redis is a blazing fast, in-memory, key-value store, that uses the disk for persistence. It's kind of like a NoSQL database, but there are a lot of cool things that you can do with it that would be hard or inefficient with other database solutions. For example, it's often used as session management or caching by web apps, but it has many other uses.

To install Redis, use Homebrew:

brew update
brew install redis

Start it through Homebrew Services with:

brew services start redis

I'll let you refer to Redis' documentation or other tutorials for more information.

MongoDB

MongoDB is a popular NoSQL database.

Installing it is very easy through Homebrew:

brew update
brew install mongo

Start it through Homebrew Services with:

brew services start mongo

I'll let you refer to MongoDB's Getting Started guide for more!

Elasticsearch

As it says on the box, Elasticsearch is a "powerful open source, distributed real-time search and analytics engine". It uses an HTTP REST API, making it really easy to work with from any programming language.

You can use elasticsearch for such cool things as real-time search results, autocomplete, recommendations, machine learning, and more.

Install

Elasticsearch runs on Java, so check if you have it installed by running:

java -version

If Java isn't installed yet, a window will appear prompting you to install it. Go ahead and click "Install".

Next, install elasticsearch with:

$ brew install elasticsearch

Note: Elasticsearch also has a plugin program that gets moved to your PATH. I find that too generic of a name, so I rename it to elasticsearch-plugin by running (will need to do that again if you update elasticsearch):

$ mv /usr/local/bin/plugin /usr/local/bin/elasticsearch-plugin

Below I will use elasticsearch-plugin, just replace it with plugin if you haven't followed this step.

As you guessed, you can add plugins to elasticsearch. A popular one is elasticsearch-head, which gives you a web interface to the REST API. Install it with:

$ elasticsearch-plugin --install mobz/elasticsearch-head

Usage

Start a local elasticsearch server with:

$ elasticsearch -f

(The -f option tells it to run in the foreground, so you can stop it with Ctrl+C.)

Test that the server is working correctly by running:

$ curl -XGET 'http://localhost:9200/'

If you installed the elasticsearch-head plugin, you can visit its interface at http://localhost:9200/_plugin/head/.

Elasticsearch's documentation is more of a reference. To get started, I suggest reading some of the blog posts linked on this StackOverflow answer.

Projects folder

This really depends on how you want to organize your files, but I like to put all my version-controlled projects in ~/Projects. Other documents I may have, or things not yet under version control, I like to put in ~/Dropbox (if you have Dropbox installed), or ~/Documents.

Apps

Here is a quick list of some apps I use, and that you might find useful as well:

• Dropbox: File syncing to the cloud. I put all my documents in Dropbox. It syncs them to all my devices (laptop, mobile, tablet), and serves as a backup as well! (Free for 2GB)
• Google Drive: File syncing to the cloud too! I use Google Docs a lot to collaborate with others (edit a document with multiple people in real-time!), and sometimes upload other non-Google documents (pictures, etc.), so the app comes in handy for that. (Free for 5GB)
• 1Password: Allows you to securely store your login and passwords. Even if you only use a few different passwords (they say you shouldn't!), this is really handy to keep track of all the accounts you sign up for! Also, they have a mobile app so you always have all your passwords with you (syncs with Dropbox). A little pricey though. There are free alternatives. ($50 for Mac app, $18 for iOS app)
• Marked: As a developer, most of the stuff you write ends up being in Markdown. In fact, this README.md file (possibly the most important file of a GitHub repo) is indeed in Markdown, written in Sublime Text, and I use Marked to preview the results everytime I save. ($4)
• Path Finder: I love OSX, it's Unix so great for developers, and all of it just works and looks pretty! Only thing I "miss" from Windows (OMG what did he say?), is a decent file explorer. I think Finder is a pain to use. So I gladly paid for this alternative, but I understand others might find it expensive just to not have to use Finder. ($40)
• Evernote: If I don't write something down, I'll forget it. As a developer, you learn so many new things every day, and technology keeps changing, it would be insane to want to keep it all in your head. So take notes, sync them to the cloud, and have them on all your devices. To be honest, I switched to Simplenote because I only take text notes, and I got tired of Evernote putting extra spaces between paragraphs when I copy & pasted into other applications. Simplenote is so much better for text notes (and it supports Markdown!). (Both are free)
• Moom: Don't waste time resizing and moving your windows. Moom makes this very easy. ($10)