An old standard with some new tricks
ATSR plays like a traditional ADSR envelope with full voltage control over attack level, sustain level, and stage times.
However, the attack and sustain levels can be modulated without changing slope time, allowing you to pass signals through the level CV inputs to the output. This turns it into a powerful tool for enveloping, crossfading, and combining signals.
With a different patching approach, you can enable sample and holds at the level inputs to create fully randomized envelopes with a single noise source.
You can even make it loop with a few different self patching strategies. This turns it into a highly tweakable LFO capable of reaching the audio range.
Whether you have it patched to loop or are using it as a conventional envelope, the three logic outputs are useful for cascading other sources.