craigslist is a big believer in open source software, and relies on Linux, MySQL, Perl, Apache, Sphinx, Redis, Haraka, and many others.

craigslist (CL) has released the following open source projects:

CL blob service - a simple HTTP-based, multi-master storage service designed for scale-out and multi-datacenter deployments:

CL image service - large scale image resizing and processing HTTP service:

memcache cluster proxy (MCP) - a high-performance modular clustering HTTP reverse proxy:

In addition, craigslist contributes code to the following open source projects:

Haraka:

Redis:

Sphinx:

The craigslist Charitable Fund supports open source nonprofit organizations including: