Slim Microframework
PHP

Slim is a PHP micro framework that helps you quickly write simple yet powerful web applications and APIs. Slim is easy to use for both beginners and professionals. Slim favors cleanliness over terseness and common cases over edge cases. Its interface is simple, intuitive, and extensively documented, both online and in the code itself.

Upload
PHP

This component simplifies file validation and uploading.

Klein
PHP

Fast & flexible router for PHP 5.3+

Idiorm
PHP

A lightweight nearly-zero-configuration object-relational mapper and fluent query builder for PHP5.

Validation
PHP

The most awesome validation engine ever created for PHP.

Requests
PHP

Requests is a HTTP library written in PHP, for human beings. It is roughly based on the API from the excellent Requests Python library. Requests is ISC Licensed (similar to the new BSD license) and has no dependencies, except for PHP 5.2+.

Carbon
PHP

A simple API extension for DateTime with PHP 5.3+

Parsedown
PHP

Better Markdown Parser in PHP.

Password Compat
PHP

This library is intended to provide forward compatibility with the password_* functions being worked on for PHP 5.5.

Spyc
PHP

Spyc is a YAML loader/dumper written in pure PHP. Given a YAML document, Spyc will return an array that you can use however you see fit. Given an array, Spyc will return a string which contains a YAML document built from your data.

PHP Paginator
PHP

A lightweight PHP paginator, for generating pagination controls in the style of Stack Overflow and Flickr. The "first" and "last" page links are shown inline as page numbers, and excess page numbers are replaced by ellipses.

ImageWorkshop
PHP

Really flexible and easy-to-use PHP class to work with images using the GD Library.

Zebra Image
PHP

A compact (one-file only), lightweight, image manipulation PHP library.

Endroid QR Code
PHP

This library helps you generate images containing a QR code.

Twig
PHP

Twig is a template language for PHP, it uses a syntax similar to the Django and Jinja template languages which inspired the Twig runtime environment.

phpRedisAdmin
PHP

Simple web interface to manage Redis databases.

ValidateJS
JS

Lightweight JavaScript form validation library inspired by CodeIgniter.

UnderscoreJS
JS

Underscore.js is a utility-belt library for JavaScript that provides support for the usual functional suspects (each, map, reduce, filter...) without extending any core JavaScript objects.

RequireJS
JS

RequireJS loads plain JavaScript files as well as more defined modules. It is optimized for in-browser use, including in a Web Worker, but it can be used in other JavaScript environments, like Rhino and Node. It implements the Asynchronous Module API.

Marked
JS

A full-featured markdown parser and compiler, written in JavaScript. Built for speed.

ChromeOS apk
JS

Run Android APKs in Chrome OS OR Chrome in OS X, Linux and Windows.

VideoJS
JS

Video.js is a web video player built from the ground up for an HTML5 world. It supports HTML5 and Flash video, as well as YouTube and Vimeo (through plugins). It supports video playback on desktops and mobile devices.

Related:

Messi
JS

Messi is a jQuery plugin to show clean, elegant messages in a simple way. With Messi you will avoid to use default JavaScript alert notifications or new windows to provide extended information to the user.

A simple, lightweight JavaScript API for handling cookies.

jQuery Storage
JQUERY

The client-side storage for every browser, on any device.

No longer maintained, superseded by JS Cookie.

EmailJS
NODE

Send e-mails, html and attachments (files, streams and strings) from node.js to any smtp server.

PixelKit UI-Kits
CSS

Free UI Kits built on Bootstrap.

Materialize
CSS

A modern responsive front-end framework based on Material Design.

Stream
XBMC

Stream allows you to stream magnet links from within XBMC, without having to wait for the whole file to download.

XBMCtorrent
XBMC

Stream allows you to stream magnet links from within XBMC, without having to wait for the whole file to download.

Service Autosubs
XBMC

Auto trigger XBMC Subtitle download if no subtitle (language) is found for a Movie/TV Show.

You Don't Know JS
INFO

A book series on JavaScript. @YDKJS on twitter. This is a series of books diving deep into the core mechanisms of the JavaScript language.

Exploring ES6
INFO

Upgrade to the next version of JavaScript.