Probably like a lot of people here I’m pretty passionate about it.
You’ve really gotta hand it to Basic Channel who kind’ve got the whole thing going in the 90’s with a Detroit/Berlin connection.
From there it’s kind’ve ballooned outwards.
An interesting side-effect, is much like vaporwave, dub-techno is a very ‘internet-heavy’ genre, a lot of it free. But it is also a vinyl heavy genre. To me it often seems like there’s two camps - proper physical release dub-techno and then internet dub-techno (if that makes sense).
I’ve been following lots of dub techno ‘netlabels’ for years, but my current fave, and probably in more ambient-dub-techno territory is the Archives label, out of Spain.
https://archivesdubmusic.bandcamp.com
Of course, you can’t go past Silent Season (Canada), who have been a slawart in the scene for years (and branching out into their own territory and style).
http://www.silentseason.com
Other members here could probably chime in on more physical release imprints but if u want a history lesson you cant go past Basic Channel, Echocord, Rhythm and Sound, Burial Mix, Echospace, Telrae etc.
I also love just listening to mixes on Soundcloud and Coltep and crew do a great regular mix called Echogarden. Also check out the dubtechnoblog for regular mixes too.
Some more old school netlabels (some defunct now, some active, … others lingering online) are Thinner label, Stadtgruen, Sublime Porte, Energostatic, Insectorama etc…
& Prob my most listened to release of all time… its just straight up
http://www.sublimeporte.net/releases/sp11/