Both are permissively licensed.
Both are embedded in billions of offerings.
Both launched around the same time.
SQLite has built a multi-million dollar annual business supporting it, while Curl I believe has not.
Curl's founder works for a small American company called WolfSSL. AFAIK he works on Curl-related stuff full time.
Interesting, where'd you hear that? :)
Haven't heard figures regarding SQLite's business side of things (yet), and doing some online searching isn't turning up anything useful.
SQLite sells support, licensing, and services using a small staff of engineers. See https://sqlite.org/prosupport.html The premium support contract is $120k/year, and it appears from the website that they have at least 4 such clients. See https://www.sqlite.org/index.html#consortium_members But even if those are all past clients, all things considered--support tiers, US domestic engineering staff, etc--it seems likely their annual revenue is at least $500K, and would not be surprising if more than $2M.
It would be interesting to hear concrete sources, though.