I have a "working" derivative of Trade Tabs (meaning it shares code) that I created some time ago, I have been using it myself without any undue issues with 4.01 (take that for what it's worth). You can find it here
AltTabs. I have never bothered to take it out of experimental status, i.e it will not show up in the Curse client, as I do not consider it finished. AltTabs takes what was in my opinion so wonderful about TradeTabs, and extends it to show the tradeskills of your alts as well, limited to the same realm. I just wish I could have found a proper way to extend TardeTabs, but to achieve what I wanted I had to repalce it completely. But without TradeTabs , AltTabs would not be around, so kudos to tardmrr! For those of you who bother to follow the link, AltTabs itself does not make the trade window "double wide", I was using another mod that does when i took the screenshot (TradeskillHD if i recall correctly). If and when tardmrr gets back to working on TradeTabs I hope he would consider incorporating my changes into his original work.
cheers!