On-the-fly GC is a concurrent mark-sweep garbage collector designed for accurate garbage collection of language runtimes written in C++ 1x. It implements the sliding views technique described in the paper “An on-the-fly mark and sweep garbage collector based on sliding views”, which is available at
http://grothoff.org/christian/teaching/2007/4705/ms-sliding-views.pdf
A goal of on-the-fly is to deliver extremely low mutator pause times, on the order of tens of microseconds, independently of heap size.
For an example of on-the-fly in action, see