It's been four years since Apple released the latest Mac OS X update for PowerPC Macs (August 5, 2009). We'll be soon four OS outdated too and I'm starting to feel like PowerPC era is finally reaching the end of the road. According to last year report from Chitika, Leopard still represents 13% of OS X web browsing. That makes us still an important mass of users today. Apple showed Mavericks to the public a couple weeks ago. One of the features shown was AppNap. I wonder if a similar feature could be ported to Mac OS X 10.5.8 or if it's too deeply integrated inside the OS. The basics are, when an app is hidden behind another window, the SO automatically slows it down unless it's doing something for the user like playing music, downloading a file, rendering in the background...etc. That is a energy saving feature for today computers, but for the old PowerPC Macs where the CPU is running at full speed much more frequently, reducing the use a background application is doing of the CPU would mean that more processor cycles are free for the active task. And it'd also save energy when the processor isn't running at full speed, so it'd also run much more cooler, which is specially important in the latest G4s and all G5s that generate a lot of heat. Other features we're missing are mostly iCloud related, like iCloud Keychain, documents in the cloud...etc. But that's a lot easier to fix. Actually, I might release a beta (free, of course) software to use some iCloud features in Mac OS X 10.5.8 through another iCloud-compatible Mac in the network (and in the future maybe without any other computer in the middle, but I can't say it for sure).