Research into Ninja Quake mod for Marco Cawthorne for his archive:
Reconstructed (approximate) release dates from news sites and file timestamps.
v0.1: ninja01b.zip
homepage news, Wednesday, December 3, 1997
shacknews: Friday, December 5 4:02pm
bluesnews: Saturday, December 6, 1997
v1.0: ninjaq1.zip
.txt file: 1998-01-27
homepage news: Friday, January 30, 1998
bluesnews: Wednesday, February 4, 1998
v1.1: ninjaq11.zip
.txt file: 1998-03-05
homepage news: Sunday, March 8, 1998
bluesnews: Sunday, March 8, 1998
shacknews: Sunday, March 8 1:22pm
v1.2: ninjaq12.zip
.txt file: 1998-05-19
homepage news: Sunday, June 7, 1998
bluesnews: Wednesday, June 10, 1998
vSE: ?
bluesnews: Jun 24, 1999
Below is a list of known releases of the Ninja Quake modification and locations where the files were known to be located (if available).
Use the internet archive wayback machine to check the links.
ninja.txt
http://crydee.sai.msu.ru/ftproot/pub/rec/games/idgames/levels/doom/m-o/ninja.txt
http://ftp.3dgamers.com/pub/games/idgames/levels/doom/m-o/ninja.txt
http://ftp.infomagic.com/pub/mirrors/doom/levels/doom/m-o/ninja.txt
http://ftp.sunet.se/idgames/levels/doom/m-o/ninja.txt
http://gamers.org/pub/games/idgames/levels/doom/m-o/ninja.txt
http://members.nbci.com/swerock/ninja.txt
http://mirrors.syringanetworks.net/idgames/levels/doom/m-o/ninja.txt
http://sunsite.doc.ic.ac.uk/packages/idgames/levels/doom/m-o/ninja.txt
http://www.cdrom.com/pub/doom/levels/doom/m-o/ninja.txt
http://www.fileaholic.com/idgames/quake2/graphics/skins/m-o/ninja.txt
http://www.fortunecity.com/underworld/wipeout/67/ninja.txt
http://www.fragzone.se/ninja/txt/ninja.txt
http://www.gamers.org/pub/idgames/levels/doom/m-o/ninja.txt
http://www.geocities.com/713_thunderbolt/images/NInja.txt
http://www.happypuppy.com/games/lordsoth/cheats/hints/ninja.txt
https://ftp.fu-berlin.de/pc/games/idgames/levels/doom/m-o/ninja.txt
https://www.quaddicted.com/files/idgames/levels/doom/m-o/ninja.txt
https://www.quaddicted.com/files/idgames2/quake2/graphics/skins/m-o/ninja.txt
https://youfailit.net/pub/idgames/levels/doom/m-o/ninja.txt
ninja01b.zip
http://www.bluesnews.com/files/patches/ninja01b.zip
http://www.fragzone.se/ninja/zip/ninja01b.zip
ninja10.txt
http://www.fragzone.se/ninja/txt/ninja10.txt
ninjaq1.zip
http://www.fragzone.se/ninja/zip/ninjaq1.zip
ninjaq11.zip
ftp://ftp.elogica.com.br/pub/warlock/ninjaq11.zip
http://www.fragzone.se/ninja/zip/ninjaq11.zip
http://www.quaketerminus.com/mods/ninjaq11.zip
http://www.quaketerminus.freeola.com/mods/ninjaq11.zip
ninjaq12.zip
http://www.fragzone.se/ninja/zip/ninjaq12.zip