# Happy seL4 day! **URL:** \ **Category:** Uncategorized\ **Created:** [July 28, 2021, 11:23pm UTC](https://sel4.discourse.group/t/happy-sel4-day/381 "2021-07-28T23:23:16Z")\ **Posts on this page:** 1\ **Page:** 1
**Author:** ![june.andronick](https://yyz2.discourse-cdn.com/free1/user_avatar/sel4.discourse.group/june.andronick/32/115_2.png) [@june.andronick](https://sel4.discourse.group/u/june.andronick)\ **Post date:** [July 28, 2021, 11:23pm UTC](https://sel4.discourse.group/t/happy-sel4-day/381/1 "2021-07-28T23:23:16Z")
On 29th July 2009, the original functional correctness proof of seL4 was completed, a widely-recognised research breakthrough and the first big milestone in seL4’s history. We obviously had a party then, and have since celebrated its anniversary, calling it, tongue-in-cheek, “International Proof Day”. On the fifth anniversary we open-sourced seL4, which was another major milestone, which we referred to as “seL4 Freedom Day”. Today marks the 12th anniversary of the proof, and the 7th anniversary of open-sourcing, and from now on we’ll refer to the date simply as "seL4 Day”. The seL4 community is now definitely global. Still we would normally have a physical party in Sydney, but won’t be able to due to the renewed Covid-19 restrictions – so we’ll all be remote 😉 Happy seL4 day everyone! A virtual toast to you all, and a big thank-you to all for your continued support!