Vita Half-Byte Loader is a project to port the PSP homebrew loader HBL to the Playstation Vita, through the PSP emulator on the Playstation Vita.

Half-Byte Loader (HBL) is an open source Homebrew Loader for the Sony PSP and the PS Vita. It allows to play fan-made games on any PSP up to firmware 6.60, and on the Vita up to firmware 1.61. HBL allows to run emulators for the Game Boy, Nintendo 64, Sega Megadrive, NES, Super NES… and many other applications.


How to Install and Run HBL

• 
  It is *strongly* recommended that you turn of all wireless connections on your PS Vita, and that you use OpenCMA on your PC instead of the regular CMA. This is recommended because otherwise your console has a way to force you to upgrade the firmware even before you get a chance to use the exploit.
  

• Extract this HBL archive in your CMA PSP Savedata folder. It is a folder on your PC named PSSAVEDATA/[lots of random characters here]. If you don’t know where it is, check your settings in CMA
  

• Connect your PS Vita to the PC through the CMA, it should give you the possibility to copy the savedata from your PC to the Vita. If not, you probably extracted it in the wrong folder.
  

• Important for owners of the European version of the game: Before running Everybody’s tennis, you need to change the language of your PS Vita/PSP to French. This is a limitation of the exploit for now, this might or might not change in future revisions. you can of course switch your console back to your own language once you are done playing with VHBL.
  

• To run HBL, start the Tennis game, select “Continue” in the Main Menu. At this point, HBL should start
  

Downloads:
VHBL r137 for Everybody's Tennis

Source

nice post +rep

Updated to r137 and added HK version