Rubber Band Library is a high quality software library for audio time-stretching and pitch-shifting. It permits you to change the tempo and pitch of an audio stream or recording dynamically and independently of one another.
MiniBPM is a fixed-tempo BPM estimator for music audio, self-contained and implemented in a single C++ file.
Dataquay is a free open source library that provides a C++ API for the Redland or Serd/Sord RDF libraries using Qt4/5 classes and containers.
Small C++ library wrapping various FFT implementations for some common audio processing use cases
Small C++ library wrapping various audio file read/write implementations
Mini Qt-based UI that can load an audio file and adjust its playback speed dynamically
Very simple sample app for Android using the Rubber Band Library
Very simple sample app for Android using the MiniBpm tempo estimator