Here is my short list of the most important open source [free] information retrieval libraries being used today that are undergoing active development as of writing. It is a mixture of engines used for both research and industrial applications.
Blog for the RepRap project
This blog is for people building a RepRap self-replicating rapid-prototyping machine to log their comments, experiences, and suggestions.
This RepRap printer will make the components using Rapid Prototyping technology, which essentially builds the component up in layers of plastic.
this is a Geographic Information System (GIS) used for geospatial data management and analysis, image processing, graphics/maps production, spatial modeling, and visualization
OpenLayers makes it easy to put a dynamic map in any web page. It can display map tiles and markers loaded from any source. MetaCarta developed the initial version of OpenLayers and gave it to the public to further the use of geographic information of all
MapGuide Open Source is a web-based platform that enables users to quickly develop and deploy web mapping applications and geospatial web services.
Welcome to the home of MapServer. MapServer is an Open Source development environment for building spatially-enabled internet applications. MapServer is not a full-featured GIS system, nor does it aspire to be. Instead, MapServer excels at rendering spati
Bioclipse is a free, open source, workbench for chemo- and bioinformatics with powerful editing and visualization capabilities for molecules, sequences, proteins, spectra etc.
