single-header topic
acutest
Simple header-only C/C++ unit testing facility.
awesome-hpp
A curated list of awesome header-only C++ libraries
criterion
Microbenchmarking for Modern C++
csv2
Fast CSV parser and writer for Modern C++
nmd
set of single-header libraries for C/C++. The code is far from finished but some parts are quite usable.
stdarc.c
Collection of small public domain file archivers
stdpack.c
Collection of small public domain de/compressors in plain C.
minih264
Minimalistic H264/SVC encoder single header library
minimp3
Minimalistic MP3 decoder single header library