RTools 4.0 is a broad rewrite of the entire code base, in the same way 3.0 and 2.0 were in the past. The main purpose of the rewrite is to compartmentalize and increase the efficiency of the connection code, while also doing some core rewrites of many of the systems which output that information, from the main scrolling window to many of the printing systems.
In addition, RTools 4.0 will change how you interface with the program, depending on what features you want from it. The current interface will be simplified a decent amount, removing EPIC, Networking, and other tools more appropriate for large tournaments. For those larger events, you will have a brand-new interface which utilizes the redesigned back-end, and will turn networking and EPIC into first-class citizens, in the same scope as today’s visual and printing interfaces.
So, where is this right now? The first stage is mostly complete. This is all the back-end translation work, which takes the data from the tournament software and turns it into a standardized container of information, as well as the creation of methods which format this information into the form that output systems will work with.
The second stage is rewriting the output interfaces, including a complete rewrite of the scrolling display, as well as all the printer displays. This should add a speed boost to these interfaces, while also condensing much of the new work that has been added since the display was first written in the pre-1.0 days.
The third stage is the rebuild of the main UI and networking components, connecting together and organizing all of the pieces.