I have noticed that certain add-ins for MS Excel produce their own tabs while others appear as groups in the Add-Ins tab for the program.

What controls this? The VBA modules carry the underlying code and forms but the images and structure of the tab seem separate (i.e. "Home" tab and clickable "Cut" image). The only other file in VBA is a .cls file which appears empty except a few small lines (in word pad). Does the xlam file have other components then? (Other than Objects/Forms/Modules visible in VBA)

What I really noticed was none of this stuff appeared in the "Customize Ribbon" command where one can change the tab order, etc. which would be nice in certain cases.

Bryan

Additionally, if somebody could recommend any good literature on making and manipulating custom ribbons, I would appreciate it!