Hi Jakub,
Geb has been around since 2010 and is not going away as far as I'm concerned.
I personally intend to maintain the project in the future. You can be assured that as long as I'm doing web development for a living it will be maintained because it's my tool of choice when it comes to automated browser testing. I am currently working on updating it to build with to WebDriver 3.x line (it already works with 3.x because the 2.x and 3.x APIs are compatible). It will involve some breaking changes so you should expect a 2.0 release of Geb in the near future.
I'm happy to start gathering names of companies who are using Geb to then put them on the website. Do you believe that it's worth starting a campaign to do so, Jakub? We can start a thread on the mailing list and announce the initiative via Geb's twitter account.
With regards to popularity, I believe it's the tool of choice for automated browser testing of most developers using Groovy on a daily basis. The site at
gebish.org has been receiving ~13k sessions a month for the last 3.5 years according to Google Analytics. I wanted to pull download statistics for geb-core artifact from maven central but the statistics section of
oss.sonatype.org seems to be broken at the moment. I will try again later and post here.
I do not plan to record any videos about Geb as I believe the documentation is comprehensive enough. There is of course a chance that I happen to give a talk about Geb in the future and it will be recorded and posted online.
I hope this helps you to make a decision whether to use Geb.
Cheers,
Marcin