[Loops] work in the exact same way except that loops CANNOT be nested in BrainfuckXT.
Why is this, exactly? I realize that this is terrible. Which is why I am working on an update. With three major changes (:D) 1. Compiling 2. Target the .NET framework 3. NESTED LOOPS!
If you are looking for a more technical explanation:
If you take a look at my interpreter's source, you can see that it reads from the source file line-by-line. Which makes parsing nested loops difficult as you cannot necessarily jump around inside the block.