On a PS3 with Custom Firmware (CFW) or PS3HEN, these are installed via the 0;145;0;4d8; Package Manager or Install Package Files menu on the XMB (XrossMediaBar).
The PlayStation 3 remains a legendary console for emulation, homebrew, and preservation. If you have modified your console with Custom Firmware (CFW) or PS3HEN, you have likely encountered and RAP files. Ps3 Pkg And Rap Files
They can be official PSN downloads or custom-made homebrew applications. On a PS3 with Custom Firmware (CFW) or