Government Outreach - software solutions for 311, citizen relationship management, code enforcement.
ActiveGovernment - their software solutions provide 311 contact centers and support and citizen service management tools, as well as automated payment management and web content management.
AINS System 311 - Markets fully integrated, web-based, workflow-driven, case management system for handling citizen complaints and requests for information.
Publisafe - markets 311 Reports for handling 311 calls and related incidents
PHPOpen311 PHP library that works with V1 of the Open311 API.
RubyOpen311 Ruby library that works with V2 of the Open311 API.
Emergency / Crisis / Disaster Management and Global Efforts
Ushahidi - a platform that crowdsources crisis information. Allowing anyone to submit crisis information through text messaging using a mobile phone, email or web form.
Sahana - a Free and Open Source Disaster Management system. It is a web based collaboration tool that addresses the common coordination problems during a disaster
The Open ISES Project - Open Information Systems for Emergency Services including the Tickets open source Computer Aided Dispatch (CAD) program
SwiftApp - The SwiftRiver project expands Twitter Vote Report into a toolkit for crowdsourcing specific types of data (this could be anything from wait times at polling stations to activity during a crisis)