I've been looking into tiling window managers because I'm tired of manually positioning and resizing all my windows whenever I want to see some information side by side. However, the tiling window managers I've investigated so far seem rather minimalist and seem mainly for rearranging terminal windows with clumsy keyboard navigation.
I'm more or less looking for a way to partition my screen and maximize a program on each partition. Bonus points if it works on Gnome.
Awesome window manager supports tiling as well as floating windows, so you have the choice. The default configuration will give you a minimalist feeling, but Awesome is so configurable that this can be changed. Full use of both mouse and keyboard is supported. Indeed, customizing it to satisfaction may take a long time, but then again at least it is possible to reach satisfaction with it.
This might be entirely off topic, so feel free to mod me down if MS Windows solutions is not what you want (the post does not explicitly say only Linux solutions). I wrote MaxTo, which partitions your screen into rectangles and changes all maximize events to put windows into those partitions. You can find it at maxto.net.
While I personally use Awesome as it provides ALL my needs (and a built-in tray), you can integrate Xmonad with both Gnome and KDE very effectively, and it's very similar to Awesome.
Compiz comes packaged with Grid now, contrary to what other posts say. Grid adds keyboard shortcuts for tiling your windows as you wish, and they are manually configurable.
Just a quick note for my fellow Mac users out there:
TwoUp by Irradiated Software lets you move windows up, down, left or right and take up 50% of the available screen realestate with a quick keypress. After using it for a day I don't think i can do without this little thing anymore.
Best thing: it's free, as in beer.
Have you looked at ion3? See also SO question about ion3 reviews.
I use xmonad with Gnome and I love it. I usually have all of my windows full-screen, so it is very easy to do that with xmonad, and then just switch window layouts when I need windows side-by-side or vertically stacked. After having used it almost a year, I find non-tiling window managers to be much more clumsy.
If you want a little bit of a feel of what xmonad + gnome is like, check out my screencast.
A partial answer to that would be to use Compiz fusion with Gnome and use maximumize (in the compiz-fusion-plugins-extra plugin):
maximumize: Resizes a window to fit within the available empty screen space
But then again it's not automatic..
I use Musca and it seems to be exactly what I was looking for! I use dzen2 to add a little panel in the corner of my screen for time etc and trayer as a system tray and it works absolutely perfectly for me.
Consider checking i3 out. It is actively developed, configuration is relatively straightforward, it isn't an obese beast, and it typically handles floating windows intelligently (including permitting resizing if it doesn't get things "quite right"). To top it off, it's well-documented and has support for 'window bars' (e.g., dzen2 or the built-in 'i3bar'). It's probably worth pointing out that there is a bit of a learning curve with respect to the key bindings -- however, it pays off in spades in terms of efficiency.
Grid plugin for compiz probably does what you want. It's essentially a copy of winsplit revolution for windows.
Here's the link: http://forum.compiz-fusion.org/showthread.php?t=8821
You should get the latest version from the git repository and compile it yourself. If you use apt you'll need (at least) compiz-dev.
Bluetile is a good option if integration with Gnome is important.
There is a nice tiling Gnome shell extension ShellTile that allows you to tile windows interactively by dragging one over other while holding ctrl. Tiled windows are grouped and behave as a one window.
Installation is easy: while Gnome >= 3.2 is running just point your browser to the extension homepage https://extensions.gnome.org/extension/657/shelltile/ and press the switch.
There is a bug in the latest version that prevents standard Gnome-shell snap window to screen sides behaviour, but it's already fixed in the development version on the Bitbucket and should land to the extensions page soon.