OpenImageIO is a library for reading and writing images, and a bunch of related classes, utilities, and applications. Main features include:

deal.II is a C++ program library targeted at the computational solution of partial differential equations using adaptive finite elements. It uses state-of-the-art programming techniques to offer you a modern interface to the complex data structures and algorithms required.

xeus-zmq provides the ZMQ transport for the Jupyter kernel protocol. This was formerly part of libxeus but was split into a separate library for xeus >= 3

The Mersenne Twister is a fast pseudorandom number generator (PRNG) that is capable of providing large volumes (> 10^6004) of "high quality" pseudorandom data to applications that may exhaust available "truly" random data sources or system-provided PRNGs such as rand|perlfunc/"rand".

This is the GNU Objective-C compiler, which compiles Objective-C on platforms supported by the gcc compiler.

Qt is a cross-platform C++ application framework. Qt's primary feature is its rich set of widgets that provide standard GUI functionality.