RTF2HTML is a name for a cross-platform C++ library (DLL, OCX) and command-line utility, which is intended to convert documents from Rich Text Format (e.g. Word, OO Writer) to HTML. Its features are tiny size, speed, low mem usage and compact output.
Haru is a free, cross platform, open-sourced software library for generating PDF written in ANSI-C. It can work as both a static-library (.a, .lib) and a shared-library (.so, .dll).