Bosshunter has also released a his own IR Shell 5 patch, similar to joshd666’s iR Shell 3.9 patch for 5.50 GEN-A & GEN-B. Bosshunter’s patch allows 5.50 GEN-A users play ISOS and also improves the stability of IrShell on Custom Firmware 5.50.
Release Notes:

Note 1: PSX games will only work with flash POP Ver (won’t work [...]

joshd666 has sent word to us of his patched iR Shell for Custom Firmware 5.50 GEN-A. He has made the necessary hex edits to allow iR Shell 3.9 to function correctly on CFW 5.50 GEN-A.
Remember this is for PSP-1000’s and PSP-2000’s TA-088v2 or less PSP’s. Don’t try this on a PSP-3000
Release text:
I was getting impatient [...]

Ahman has released iR Shell v5.0, this new very is a big step up from the other 4.xx versions as it introduces PSP multi-tasking (PSP Slim only) Just check out the above video and I’m sure you be impressed. Good job Ahman!
Notes and iRShell v5.0 Usage:
Usage Notes:
1. Before you can use the Advanced Multi-tasking, you’ll [...]

PSP Homebrew developer AhMan has released an update to his shell replacement iR Shell. This is an important release as it adds support for Dark_AleX’s legacy homebrew enabler aka LEDA. Also a new added feature which allows emulated PSX games to run at a smooth 30FPS through the use of RemoteJoy.
Source: iR Shell 4.92 Released
iRShell [...]

AhMan has released an update to his homebrew application iR Shell, the PSP shell replacement. This release brings us new PlayStation Network title support. There is also an option for disabling Magicgate protection in order to speed up access times on non Magicgate memory sticks.

AhMan has released an update to iR Shell. This update adds some extra enhancements with PSP Slims extra memory and a few bug fixes. Full change log below:
New Features for PSP Slim:
- Added support to homebrews that are built with the option PSP_LARGE_MEMORY, that is, to use the extra slim memory. When running these homebrews [...]

AhMan has released iR Shell 4.7, the complete shell replacement for the PSP. This new version adds support for 5.00 M33 firmware as well as many other changes, listed below.
Changelog:
* Support Dark_AleX latest 5.00M33-3 CFWs. Users of original 5.00M33 & M33-2 should upgrade to M33-3 to avoid incompatibility issues. The latest Popsloader 5.00 is also [...]