Yeah, that sucked for sure and we hated to disappoint people like that (co-founder here). But you have it exactly backwards. FoundationDB was never open source. There was a binary that you could download and use as a trial, or you could buy a license for real use. The users that bought licenses got to keep using those licenses. Some of those customers went on to build billion-dollar businesses on top of FoundationDB (Snowflake!) A few years after acquiring the tech Apple themselves open sourced it (!) so now it is open source. The big challenge for users is that most of the sophisticated "layers" that make the tech into more of an easy-to-use database rather than just a storage engine are still proprietary.
Yea it was over 8 years ago, I didn't work on the team so I don't remember all the details - I just remember this decision impacted them hugely. Hopefully it worked out well for you, but the decision - weeks from their launch - impacted their mental health, as well as the project.
It was never open source before apple. Rather the binary was freely available to be used. When apple bought them they took it away but continued to support customers with contracts. In that way it was inaccessible until it was open sourced.
Yes, I got bitten by this and will never forget- FDB abruptly shut off public access in mid-2015. Fortunately for me, it only cost half a day to migrate my system to Postgres.
I'm sorry I mis-remembered the exact details of another team that I didn't work on and tech stack from 8 years ago. I'll go give myself 100 hail Marys.
The point wasn't to bash Apple - the point was that the team lost a lot of money and time and shipped and inferior product because Apple chose to purchase and close down part of the stack.
Apple then bought it up and shut the open source down. They had to rebuild whole layers from scratch.