Following on from the Acid Tapes post. I'd also like to promote Music & Elsewhere, established and run by Mick Magic from the band Magic Moments At Twilight Time.
M&E started as a demo label in 1987 and became a fully-fledged distribution service in 1992. M&E provided an outlet for the MMATT projects as well as releases from numerous underground bands. By 2003 it had 599 titles on its label including many promotional compilations including the behemoth "Decadion" (M&E 400, 1997). An A-Z listing of all the bands and comps is presented in the M&E "Catty Log" http://www.mickmagic.net/The%20Catty%20Log.htm
Alas Mick sold the back catalogue master tapes to an Italian collector a few years ago but a smattering can still be found on Soulseek or Discogs. To celebrate the 30th Anniversary of M&E in the New year Mick will be publishing a rolling feature via his website http://www.mickmagic.net/Index.htm called "The A-Z Of Music & Elsewhere", which will collate all the M&E band/artiste tracks already on it and also add those previously issued on the deleted "Decadion" data discs. Ultimately, the plan is to have at least one freely downloadable track on there by every band ever released, from Acidfuck to Zerobranco, at a couple of letters a month.
United World Underground was a somewhat a short-lived attempt at rebranding M&E in 2000, providing an outlet for bands from around the world. Mick chose the title UWU as in his own words "I wanted to go with something that I thought more captured the full scope of the project, and it sounded cool as fuck... in English! And there was the irony; it sounded crap if you tried translating it into any other language! But it did make a very good 'umbrella title' for the whole thing; MMATT, M&E and the whole network; all our friends and contacts around the global counter-culture movement"
To commemorate the 25th Anniversary of M&E and UWU in 2017, two MONSTER compilations were released that showcase the best of the best from the back catalogues. Containing over 60 hours of music these retail for £30 for both, or £17.50 apiece (incl. P&P)
You can check the bands/artists and song titles at these two links.
Since 2019 Mick has been involved in a collaborative project called "Magic Bullet" which he describes as "broad spectrum experimentalism", the full listening experience can be found on their Reverbnation page at https://www.reverbnation.com/magicbullet8/songs
I myself am a big fan of X-Ray Pop, Animal Factory, Cosmic Dance Society, The Witches to name but a few. I hope you find something of interest from the info provided.