Official site
https://cnc-comm.com/red-alert-2
Play in browser
https://chronodivide.com/
Dox
https://oldgamesdownload.com/wp-content/uploads/Command_Conquer_Red_Alert_2_Manual_EN.pdf
Map editor and patches
https://cnc-comm.com/red-alert-2/downloads
Maps
https://www.gamemaps.com/ra2/maps
https://www.cnclabs.com/downloads/redalert2/
https://forums.cncnet.org/topic/3806-ra2-yr-maps-a-ginormous-collection-of-maps/
Strategy guide
https://gamefaqs.gamespot.com/pc/914165-command-and-conquer-red-alert-2/faqs/9349
Mods
https://www.moddb.com/games/cc-red-alert-2/mods
Portable "Red Alert 2" (from Flecktarn (http://"http://'https://www.corrupt.org/boards/index.php/topic,185.15.html'"))
https://archive.org/details/red-alert-2_202103