QXmpp is a cross-platform C++ XMPP client library based on Qt and C++.

Library for Qt-based Matrix chat clients. It is required by
Quaternion.

The motivation behind the project is to provide a native desktop app
for Matrix that feels more like a mainstream chat app.

All the little tools you need to get your work done.

pdf2djvu creates DjVu files from PDF files. It's able to extract:
graphics, text layer, hyperlinks, document outline (bookmarks) and
metadata (including XMP metadata).