AmhCode
A paclet full of legacy code from a few years ago. Mostly depends on a python-style object system.
BTools
A general purpose package that implements useful functionality for application development. Features include: distribution tools, documentation generation, front-end manipulation, and application editing
BugTracker
A little framework for tracking bugs
ChemTools
A collection of packages for object oriented chemistry.The primary packages implement an object and data framework.Support is included for basic spectroscopy and a few different external programs.A moderately sophisticated discrete variable representation framework is included as well.
CuratedData
A package for building custom curated data functions
CustomServiceConnection
A package for building custom service connections functions
DocGen
A paclet for generating documentation. Both notebook and HTML docs are supported. Also supports automatic documentation generation. Forked from BTools.
EasyIDE
An IDE for Mathematica. Supports tabbing, file browsing, plugins, customizable stylesheets, extension specific tweaks and toolbars, and is reasonably customizable
Ems
A static website builder like pelican or jekyll. Comes with built in themes and the ability to develop one's own.
ObjectFramework
A framework for creating and using objects in a vectorized manner