Sequoia is a software library for musical step-sequencing, with generative capabilities and sample-accurate timing. The architecture supports a variety of techniques, including polymetric sequencing, clock division, probability, and other parameters which can be manipulated in real time – or even sequenced themselves. The core library is written in C and supports JACK MIDI; Python bindings are also available.
A conference paper introducing the library can be found here. A presentation and demo can be seen here. The Git repo is hosted here.
Epicycle is a GUI application I use to test and demo Sequoia; a screenshot is shown below.
Ziggurat main window