A collective list of free APIs

Source code syntax highlighting for OneNote 2016 and OneNote for O365 . NoteHighlight 2013 port for OneNote 2016 (32-bit and 64-bit)

EAF, an extensible framework that revolutionizes the graphical capabilities of Emacs

Recipes and build machinery for the biggest Emacs package repo

Project Interaction Library for Emacs

wxPython's Project Phoenix. A new implementation of wxPython, better, stronger, faster than he was before.

Sequence manipulation library for Emacs. Included in Emacs 25

Major mode for editing Jenkins declarative pipeline syntax

ESUP - Emacs Start Up Profiler

An Emacs mode for editing and running Microsoft PowerShell code.

Emacs major mode for editing Robot Framework files.

Emacs flymake handler for python using pyflakes

Company backend for Python jedi

The long lost Emacs string manipulation library.

Minor modes to highlight indentation guides in emacs.

Emacs Python Development Environment

A JavaScript code analyzer for deep, cross-editor language support

Python virtualenv API for Emacs Lisp

Visual Popup Interface Library for Emacs

Python auto-completion for Emacs

A RPC stack for Emacs Lisp

Prelude is an enhanced Emacs 25.1+ distribution that should make your experience with Emacs both more pleasant and more powerful.

Python virtual environment interface for Emacs

COMPATibility Library for Emacs Lisp

Jupyter notebook client in Emacs

Emacs bindings to ØMQ

Extensible Emacs HTTP 1.1 server

A websocket implementation in elisp, for emacs.

Modular in-buffer completion framework for Emacs

Emacs Markdown Mode