NetBird- tail scale but fully open source with web hi, built in or bring your own auth, clients for pretty much everything, and really powerful network separation and segregation functions, along with posture checks and tons more.
Netbird does some things better than Tailscale. But honestly tailscale is just so much better. It takes a much more "it just works" approach which for our office we much prefer. It was so much more fiddly and just awful.
Netbird also kept pissing me off because we'd have a route to the office, and if you're in the office it would just kill all network traffic as it tries to go to itself instead of the default gateway and just never works. Tailscale kinda has the same issue, but it doesn't end up in an endless loop it just routes all your traffic in the office through the VPN.