Bitcoin XT
Software / App
A proposed software upgrade for Bitcoin with a two megabyte block size limit, which ultimately did not achieve mass adoption.
Mentioned in 2 videos
Videos Mentioning Bitcoin XT

Nic Carter: Bitcoin Core Values, Layered Scaling, and Blocksize Debates | Lex Fridman Podcast #173
Lex Fridman
One of the early competing Bitcoin implementations that supported a large block proposal, which did not achieve consensus during the block size wars.

Satoshi Nakamoto and the Civil-War Within Bitcoin
ColdFusion
A proposed software upgrade for Bitcoin with a two megabyte block size limit, which ultimately did not achieve mass adoption.