mod_auth_openidc is a certified authentication and authorization module for the Apache 2.x HTTP server that implements the OpenID Connect Relying Party functionality.

pdfsandwich generates "sandwich" OCR pdf files, i.e. pdf files which contain only images (no text) will be processed by optical character recognition (OCR) and the text will be added to each page invisibly "behind" the images. pdfsandwich is a command line tool which is supposed to be useful to OCR scanned books or journals.

D-Bus is a message bus, used for sending messages between applications. Conceptually, it fits somewhere in between raw sockets and CORBA in terms of complexity.