There is a large program library for Icon. It is an excellent resource for both new and experienced programmers. The library contains numerous examples of how to do things with Icon. The library also provides many useful applications, as well as hundreds of procedures that supplement Icon's built-in repertoire. Idol is an object-oriented extension to Icon that provides concepts such as classes and multiple inheritance.
Idol is written in Idol and is distributed as part of the Icon program library.
Idol runs on almost all of the platforms that support Icon. New material is added when it's available. Established implementations usually are updated only when there's a major new release. This typically is every year or two. The Icon program library is updated on a similar schedule.