Looper's Delight - is one of the first web-sites dedicated to loopers. It was founded by Kim Flint in 1996. Sad news came in 2010 – Kim was killed in a bike accident. The site is no longer kept to date, but this resource is still useful in many aspects.
vguitarforums.com - the biggest forum for Roland VG and GR systems owners.
guitarmoderne.com - The Zine for Adventurous Guitarists. One of the best internet sources dedicated to unconventional guitar approaches and suchlike.
Mobius looper - the best and the most powerful software looper ever made. And it is FREE! Both Mac and Win. Works as standalone and as VST plug-in in DAWS like Cubase or Ableton Live! Ed Sheeran's "Chewie Monsta Looper" is simply a midi foot controller made by his guitar tech for Mobius run on a laptop.
dgmlive.com/word - King Crimson Family web-site and blogs. Robert Fripp blog.
joness.com/gr300 - if you are interested in the history of Roland GR synths check this highly informative resource by Wayne Scott Joness.
livelooping.org - a site that "shows you what Livelooping is about and how it is made!". Not generally about Ambient music, but much info about looping methods, tool, articles and musicians.
loopermusic.com – detailed looper pedal reviews.
ambientonline.org - Ambient Guitar Discussion thread on the forum.
Lessons and tutorials
"How To Create Ambient Guitar Sounds" article on Dawsons Music - a company that was established in 1898 in Warrington, England, making it the oldest retailer of musical instruments in the UK.
"Ambient guitar techniques" article by Nicholas Kula on tonereport.com
"The Ambient Guitarist's Toolkit" article by Dave Eichenberger on seymourduncan.com. Yes, Seymour's lobby)
Books and articles realted to Ambient music
"Ambient Music" by Eliot Bates, 1997. A serious academic research. 233 pages. PDF.
"Brian Eno: His Music And The Vertical Color of Sound". Great book by Eric Tamm. 211 pages. PDF.
"Robert Fripp: From Crimson King to Crafty Master". Another great book by Eric Tamm. 94 pages. PDF.
"Neither scene nor heard: a journey through ambient music" - a substantial article about the history of Ambient music and characters in the play. Published on A Strangely Isolated Place (ASIP) - a music blog (created in 2008), community and record label (started in 2012).
"How Brian Eno showed the potential of ambient music" article by Nick Mitchell
"Ambient music, Beginnings and Implications" - Masters-degree Dissertation (1995) of Chris Melchior
"Monotony and the sacred: a brief history of drone music" article by David Rutledge.
iOS
samplr.net - this is on of the few apps I use in my live performances. Samplr lets you make music and play with sound in a new and intuitive way by touching the waveform on the screen directly with your fingers. 5 sound effects, 6 simultaneous samples (with 8 voices each) and 8 different ways to interact with the sound. All modes are Multi-Touch ready. With an interface designed for live performance, Samplr gives the musician quick and precise access to all the instrument functionality at any time.
borderlands-granular.com - this is on of the few apps I use in my live performances. A very popular app with electronic and experimental music performers. "Explore, touch, and transform sound with this new interface for granular synthesis, a technique that involves the superposition of small fragments of sound, or grains, to create complex, evolving timbres and textures."
loopyapp.com - the most popular iOS looper. Simple, but powerful.
soundfruuze.com - this is serious. The guy who develops this app - Alexey Nadzharov - is a fantastic pianist, academic noise music performer and music software wizard.
Online Soundscapes
ambient-mixer.com - is a community driven project offering some unique quality soundscapes with different atmospheres for chilling, relaxing or your recordings using site's endless audio loops. You can further effectively mix and create your own sounds absolutely free, with no software installations required. Now attention! All atmospheres are royalty free audio files and you can use them even in your commercial projects, thanks to the Creative Commons Sampling Plus license.
noisli.com - I use this app on my performances from time to time. Good for filling audio space with something simple and relaxing, for example when preparing setup for a new composition.
naturesound.tk - is "a cozy and quiet corner of the Internet". Audio + Video. There’s an option for full-screen view - should be fine for your huge plasmas...
meditationroom.org - free streaming audio and video. Nature sounds / relaxing music / guided meditations / binaural beats.
noises.online - minimal design with some tweaking options. Sounds on this website are streamed for personal use only.
asoftmurmur.com - one more site with a simple design.