All the work necessary to produce a piece of software such as Rwm would be next to impossible to achieve in a small project. Consequently it is based on the work of others as well as my own. Some of the others are mentioned on this page.
I use Debian as my linux distribution. For development I use the testing - currently Sarge - version, that will in time become the next stable version of Debian. I found the testing version to be reasonably stable for developer work, with very few exceptions that are usually easy to be fixed.
For production environments, such as web servers, I stick to the stable versions - currently 3.0 or Woody.
Essential for the development of Rwm is the Qt toolkit, which is a cross platform development toolkit for Graphic User Interfaces ( GUIs ). As of this writing the current version is 3.3.4, with the version 4.x in beta status. I have been using it for years now, whenever I needed a GUI for one of my projects, and it makes the task of creating and designing a GUI really easy. You will still have to write some code yourself, though.
I am sure I'm not the only one who uses Christophe Tronche's compilation of docs on the Xlib. Without it I would have run out of understanding the Xlib at the early stages of this work.
The basics on window managing. Off the top of my head I dont't know the relevant links, but I promise to look them up at the next opportunity.
There are too many out there to list every one of them here. I will just mention the ones I had a look at ( and still remember having done so ) or have actually used.
First kwin comes to mind, the window manager for the KDE Desktop. As KDE is based on Qt, it comes near to what I want to do with Rwm. Rwm however will not be as bloated as kwin is.
Some good ideas went into the early versions of aewm++, I have adopted some of them. aewm++ is written in C++, which made it especially attractive to me. In later versions however the developer dropped the ability to work with extended window manager hints, leaving aewm++ at a level that is of little interest for me.
Another C++ written window manager is blackbox. I have used it - with some Qt enhancements of my own - for quite some time and would use it still, if I hadn't the functionality of Rwm in mind.
flwm is another C++ written window manager that I used for some time. It is based on a quite different toolkit called FLTK. As my favourite toolkit is Qt however, this offers no usable insights in that area, but is a well made - if somewhat minimalistic - window manager. It was the first one I had seen that offered both horizontal-only and vertical-only maximizing of windows.
icewm is a window manager I have installed, but rarely use. But I have glanced through the sources and found some insights there that I was not able to find elsewhere.
Finally I want to mention qlwm. This is an early attempt to write a Qt based window manager, but didn't fit my needs in any way. I found it not very usable.
You will have noticed that I have failed to provide some links, most likely links to other window managers. This is due to the fact that I'm writing these pages at home, with no connection to the inet. I will supply the missing links asap, but bear with me: I am in the office but once a week.