GitHub: Build software better, together.
BitBucket: Git and Mercurial code management for teams
Visual Studio: Comprehensive collection of developer tools and services.
Swiftype: Add great search to any website. Free with limitations.
Coveralls: Test coverage history and statistics.
LingoHub: Free for Small Teams, Open Source usage and Educational projects.
Codacy: Continuous Static Analysis designed to complement your unit tests.
TinyCert: Free SSL certificates for your startup.
Pingdom: Website monitoring. Free for one website.
Rollbar: Full-stack error monitoring for all apps in any language.
Loggly: Simplify Log Management Forever. Free for one user.
Getting Real: The smarter way to build web apps. A free book by 37signals.
Peek: Get a free, 5-minute video of someone using your site.
Cody: A free library of HTML, CSS, JS nuggets.
Website Builders
HTML5 UP: Responsive HTML5 and CSS3 site templates.
Bootswatch: Free themes for Bootstrap.
Templated: A collection of 845 free CSS & HTML5 site templates.
WordPress.org: Create your new website for free.
Strikingly: Free, unlimited mobile optimized websites for strikingly domains.
Bootstrap Zero: The largest open-source, free Bootstrap template collection.