iPlotz : Wireframing, mockups and prototyping for websites and applications
DokuWiki : DokuWiki is a simple to use and highly versatile Open Source wiki software that doesn't require a database.
PhpWiki : PhpWiki is a clone of the original WikiWikiWeb
iceScrum : Free and OpenSource platform for your agile developments
RAWGraphs : RAW is an open web tool to create custom vector-based visualizations on top of the amazing d3.js library.
Primarily conceived as a tool for designers ...
OpenRefine is a powerful tool for working with messy data: cleaning it; transforming it from one format into another; and extending it with web services and external data.