aMSN is an open-source MSN client written in Tcl/Tk. It is probably the best MSN client I've found for Linux, which is one reason why I love it (love it because there is nothing better, awesome). I also love it because it is more customizable than regular MSN, it uses less memory than regular MSN (somehow), and it doesn't use ads.
Now for the fun part. Why does aMSN suck? The first thing that you will notice about it is the look. Before I get started, I will say that the developers have done an excellent job in this department compared to previous versions. Anyway it doesn't look so good. Being written in Tk, which is an inherently hideous library (looks like it's from a ghost of OSs past), the menus and dialogs look like garbage and do not fit into any theme. Under Windows it looks even more like garbage, with random colourings everywhere (who made checkboxes with a red background? First time you see it you think they are already checked). Also under Windows it never remembers any settings. So every time I restart the computer - which in the Windows world is a lot - I have to click the "I would like to minimize to system tray" when I click close. Nor does it remember any of the other settings like fonts or layout, so it just reverts everything to the default. Not that the default is that bad, a rare thing among open-source software, but I like a little bit of customization and I don't like having to redo my customizations every time I start the program.
For external programs like browsers, file browsers and opening files, it would be nice if aMSN figured it out for you what to do. It's easy to fix this, but annoying nonetheless (especially for non-computer-savvy people who wouldn't bother to check and would probably just dump the software). It would also be nice if the preferences dialog fit on the screen so that I could push the "Save" button without having to resize or move it. I have a fairly high resolution so there shouldn't be a problem here.
The final thing I have to say about this is it's stability. For the most part, the app works fine. However when the network goes down, the app freezes temporarily. If I click a menu, it shows the grey box after a while but with nothing on it. The repainting stops working and I don't see anything at all on the window. It also slows the rest of my system down a bit (weird on a dual-core CPU). This is slightly annoying when it happens, but the other day it happened while I was running two Java apps (Azureus in the background and Netbeans) which already used up most of the system's resources. Well that caused the entire system to lock up for about ten minutes before I pushed the reset button. This leads off-topic into the question of Linux's stability. The claim is that Linux freezes far less than Windows, however I find that Windows never freezes for me unless a driver is broken (which also happens in Linux). Linux on the other hand freezes when: a bug in GNOME or Compiz Fusion crops up (not so often with Gutsy but fairly often under Feisty), or when Java, aMSN or another one of the many programs written in a slow-ass interpreted language eats all my system's memory. I have 1GB of memory! Where does it go? Anyway this rant will be saved for another day.