Here is a hack that I began back in 2007. I lost interest in it and put it on hold and uploaded what I had so done at the time.
After playing various Megaman hacks, I was inspired to start work on the project again.
Edited Megaman X to look like Zero. Changed Title Screen.
Changed 90% of dialogue.
Edited Get Weapon Portrait to look like Zero.
Changed Dr. Light into Dr. Wily.
Edited Boss select screen "Megaman X" icon into "Z"
Zero can use the upgrades given to him, but his armor looks the same.
I am still working on editing those sprites.
Also, Zero has no ponytail. I apologize for my lack of asm coding knowledge, but I am hoping this hack will inspire someone to find a way to include his hair.
I will be releasing a patch later this month.
Also, I want to thank Justin3009, Xstuff, and Protorock for helping me with this project and for answering my questions.