There are ALOT of differences. To many to meantion here, but I shall attept to give it a go and name the main ones.
Windowblinds- Skins the explorer shell (winxp blue to make it look different).
- Can make oversized start buttons and glow effects.
Thats really the basics of windowblinds. Not a whole lot more to it than that (minor things like wallpaper changer, and alpha transparent windows are included).
Desktop X- Widgets and gadgets. These can display anything from weather to RSS to searches and dictionaries. LOTS of possibilities here.
- Windows Themes. This can include anything that you want to put in it. Widgets, complete startbar replacement, hover effects. LOTS of possibilites here also.
I recommend that you check out a few widgets and themes for Desktop X. Then check out a few skins for windowblinds.
Then of course, you'd probably want to get both lol

. And to be honest, I'd really just buy object desktop. You get a HUGE load of amazing programs (including desktop x and windowblinds) as well as updates and betas. Its well worth the money for sure.
Hopefully this helps you decide. If I were forced to buy just 1 of the 2 programs, I would personally go for windowblinds. It kicks ass

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