Mozy open-sourced several of their libraries, Ruby Protocol Buffers and Mordor. Mordor is a high-performance C++ I/O library that uses cooperatively scheduled fibers instead of callbacks, which is supposed to put less load on the kernel.
There are some Mordor YouTube presentations
- Introduction to Mordor
- Mordor: Fibers and Schedulers: Part 1, Part 2, Part 3, Part 4
- Mordor: HTTP Client/Server: Part 1, Part 2, Part 3, Part 4
- Mordor: Streams: Part 1, Part 2
Like any library, it has a lot of infrastructure along with the stated purpose.