ypsilon is the implementation of Scheme Programming Language, which conforms to the latest standard R6RS. It achieves a remarkably short GC pause time and the best performance in parallel execution as it implements “mostly concurrent garbage collection”, which is optimized for the multi-core CPU system.
If you are wondering “Why yet another Scheme implementation” you can find the answer here. To sum it up: they require real-time processing speed and can not use Boehm Garbage Collector because they run on arcade consoles or pinball machines, so, they had to start from scratch.
Ypsilon 0.9.6 is the bug fix release. It fixes all bugs reported and
found in version 0.9.5. Ypsilon 0.9.6 has passed all 8886 tests in PLT
R6RS test suite revision 11016.