The Linux Foundation will soon have Twitter as it's member. The foundation is expected to announce Twitter's joining next week during LinuxCon.
Twitter is a heavy Linux user as its services are powered by open-source technologies, most notably the Bootstrap framework. Also, Twitter's infrastructure is powered by thousands of Linux servers which keep its services alive.
Chris Aniszczyk, Manager of Open-source at Twitter said in a statement, "Linux and its ability to be heavily tweaked is fundamental to our technology infrastructure. By joining The Linux Foundation we can support an organization that is important to us and collaborate with a community that is advancing Linux as fast as we are improving Twitter."