Plugins developmentΒΆ
The helpfile Writing Unit Generators covers what you need in order to create a UGen plugin (including Xcode instructions for those on Mac).
Plugins are dynamically loaded libraries (DLLs) written in C++.
The official SuperCollider Book has a chapter Writing Unit Generator Plug-ins
by Dan Stowell.
A tutorial on how to write C++ plugins can be found on the forums