Major projects can be seen at: Section "The most important projects done by Ciro Santilli".
A summary of minor projects is given at: Ciro Santilli's minor projects.
This section is a dump for anything else, to keep those sacred first sections that show on the top of the homepage clean.
CommonMark is a good project. But its initial release method was not very nice, they first developed everything behind closed doors with the big adopters like GitHub and Stack Overflow, and only later released the thing read, thus wasting the time of people who were working on alternative in the meanwhile, e.g. github.com/karlcow/markdown-testsuite which Ciro contributed to: Ciro Santilli's minor projects.
GitLab was very important to Ciro because he wanted to base Booktree on it.
See also: Ciro Santilli's minor projects.
Ciro Santilli was contributing to this, when CommonMark left private mode and killed it, thus wasting many hours of Ciro's time.
See also: Ciro Santilli's minor projects.
Ciro Santilli contributed a bit to this, and was even given push rights, see also: see also: Ciro Santilli's minor projects.
Ciro Santilli has sometimes wasted time with low impact projects such as those listed at Ciro Santilli's minor projects instead of doing higher impact projects such as those mentioned at: Section "The most important projects Ciro Santilli wants to do".
But maybe "Everything you did brought you where you are now." applies, maybe it is during the "low impact activities" that one gets the inspiration and experience required for the "high impact ones".