Thanks! I was also surprised that there are very few tools to work with the seekable format. I could imagine that at least some people have a use-case for it.
Yes, the name is a combination of zstd and seek. Funnily enough, I wanted to name it just zeek first before I knew that it already exists, so I switched to zeekstd. You're not the first person asking me if there is any relation to zeek and I understand how that is misleading. In hindsight the name is a little unfortunate.
Why zeek, BTW? Is it a play on "zstd" and "seek"? My employer is also the custodian of the zeek project (https://zeek.org), so I was confused for a second.
[1] https://github.com/SaveTheRbtz/zstd-seekable-format-go