PlayStation Portable homebrew refers to the process of using exploits and hacks to execute unsigned code on the PlayStation Portable (PSP). Applications Additional features added including the ability to emulate and play the ROMs of other consoles, play homebrew games, share music, print photos, watch videos from streaming sites such as YouTube, and run additional video formats originally unsupported by the device. Emulation Homebrew emulators were created for NES, SNES, Game Boy Color, Game Boy Advance, Sega Genesis and Nintendo 64 console systems among others. Numerous different emulators were created for the most popular consoles. PlayStation 1 emulation was native, made by Sony. Demoscene The reverse engineering process to understand the PSP hardware started shortly after the advent of homebrew unsigned code execution. This effort led to development of Toolchain and SDK by enthusiasts and paved the way to utilise vector floating point co-processor, GPU and audio capabilities of the device without asking Sony for permission. Several demoscene non-interactive creations were released targeting PSP such as Suicide Barbie, purely to demonstrate optimisation skills of the developers and the power of the handheld. History Soon after the PSP was released, hackers began to discover exploits in the PSP that could be used to run unsigned code on the device. Sony released version 1.51 of the PSP firmware in May 2005 to plug the holes that hackers were using to gain access to the device. On 15 June 2005 the hackers distributed the cracked code of the PSP on the internet. Hackers refused to apply updates which would render their hacks unusable so Sony attempted to convince users that there was a benefit to upgrading by including new features in the firmware updates, such as a web browser, and not just security patches to plug the vulnerabilities. BusinessWeek dubbed this the "carrot-and-stick" approach. In August 2005 Sony released version 2.0 of the firmware which included the web browser, file compatibility updates and other features. Hackers and other homebrew enthusiasts then encountered the first trojan for the PSP. Symantec called this trojan "Trojan.PSPBrick". Users attempting to downgrade their PSP using this software instead found that it was rendered inoperable as this software deleted mandatory/important system files. Over the course of 2005 Sony released six different versions of the firmware and hackers typically responded to it by downgrading to avoid the new security updates. In mid-2006, after several months of problems in defeating the