In short: It’s the version Capcom should have released.
The patch is a ROM hack created by members of the Rockman EXE translation community (most notably and the team at The Rockman EXE Zone ). It takes the original Japanese Rockman EXE 6 ROM (either the regular or the “W” edition, which includes minor fixes) and transforms it into a full English-language version — but unlike the official localization, it keeps all Japanese content intact.
Extensive sidequests and boss fights featuring characters from the Boktai (Solar Boy Django) series, including the legendary Count of Groundsoaking.
The primary reason fans seek the Rockman EXE 6 translation is to access the "lost" content that never made it to the US/EU releases: