Self 4.4 and patents issue

[Carter Cheng]

Hi,

I have been thinking about doing some implementation work and writing a self like system where self is the embedded language. I am curious to what extent the ideas in self are patented or in the public domain (especially w.r.t. various optimization techniques described in the literature). Is it feasible to undertake such a project and release it under an OSS licence?

Thanks in advance,

Carter.