Sony PS3 Firmware 2.50 & PSP Firmware 5.0 Released - SlashGear
Dual Boot: PS3 Official + Custom Firmware CFW 3.66 Coming Up
I purchased a PS3 backward compatible from ebay for a good price and I'm impressed how clean it is. However... It's still on firmware 2.50. Should I update the firmware? : r/PS3
PlayStation 3 - Wikipedia
PS3 Firmware 4.30 Brings Vita Trophies To PS3, Removes Folding | TheSixthAxis
PS3 System Software 4.86 Update Live, Don't Update Your Firmware! | PSXHAX - PSXHACKS
PlayStation Home Online 1.86 Running on PS3 4.88 Official Firmware (OFW) | PSXHAX - PSXHACKS
PS3™ | System Update
PS3: Official Rebug 4.81-REX/D-REX with COBRA 7.31 released - Hackinformer