I've formed a positive opinion of Parham's character by the way he's conducted himself over the years. And Solid Queue isn't a serious Sidekiq replacement for the types of high volume applications where you'd want a Sidekiq license; I doubt he even sees it as a threat.

Just to echo those sentiments, Mike Perham has appeared on a panel discussion recently with his 'competitors', including Solid Queue.

https://www.rubyevents.org/talks/panel-the-past-present-and-...

Do a Google search for Sidekiq DHH. First link is about migrating from Sidekiq to Solid Queue. Third result (for me anyway) is a Reddit thread where Perham talks about trying to make Basecamp a customer and that he wasn't able to...