FFmpeg is a complete, cross-platform solution to record, convert and stream audio and video. It includes libavcodec - the leading audio/video codec library.
Readium.org: Open Source Technology for EPUB 3 and the Open Web Platform The Readium Foundation (Readium.org) develops technology to accelerate adoption of EPUB 3 and the Open Web Platform by the global digital publishing industry. Readium.org was formed in February, 2013 as a non-profit memebership organization. Current Readium.org projects include Readium Web (an EPUB 3 rendering engine for browser-based cloud readers) and Readium SDK (an EPUB 3 rendering engine for native apps).
The eXtensible Text Framework (XTF) is a powerful open source platform for providing access to digital content. Developed and maintained by the California Digital Library (CDL), XTF functions as the primary access technology for the CDL's digital collections and other digital projects worldwide.
The D-Net Software Kit is an Open Source service-oriented solution for the construction of customized Data Infrastructures. Data Infrastructures address the need increasingly manifested by research communities to operate over the integration of content collected from several information sources (such as institutional repositories endowed with OAI-PMH interfaces, or archives of research data).
wer sich von facebook & Co. verarbschieden will, für den ist vielleicht interessant ein "eigenes" social network aufzubauen - social networks: auch zur Begleitung von Lehr-Lernprozessen interessant!