Half Byte Loader (also known as HBL) is an open source software project

Half Byte Loader (also known as HBL) is an open source software project that aims at loading homebrew for PlayStation Portablehandheld console through user-mode exploits. It does not provide any mechanism for loading official games or ISO images. HBL was built from scratch to be easily portable to any user-mode exploit. The project was created and started by m0skit0 and ab5000. It is currently maintained by wololo. Until the mid-1990s, updating firmware typically involved replacing a storage medium containing firmware, usually a socketed ROM. Flash memory allows firmware to be updated without physically removing an integrated circuit from the system. An error during the upgrade process may make the device non-functional, or "bricked". The driver can also get in-dash information while driving in this manner, such as real-time fuel-economy and tire-pressure readings. Local dealers can update most vehicle firmware. The PSP was originally to have a simultaneous PAL region and North American launch, but on March 15, 2005, Sony announced that the PAL region launch would be delayed because of high demand for the console in Japan and North America. A month later, on April 25, 2005. HBL was created initially for the Medal of Honor Heroes exploit. An alpha version was released as open source by m0skit0 and ab5000 on November 2009, which ran very simple homebrews. When the Patapon 2 demo exploit was found and leaked, wololo joined the project and proposed to port HBL to this new exploit. The AdvancedPSP forums, which hosted the project, were shut down by the hosting and the project moved to wololo/talk[15] forums. wololo also created a new public SVN repository for HBL at Google Code. Other PSP hackers such as Davee and neur0n joined in to help the development of this port. HBL for Patapon 2 passed to beta version, and can be considered the first useful HBL version, released on March 2010. HBL was subsequently ported to several other user-mode exploits, and also served as base for other projects, like the PRO CFW project.