How many Publishers does
AUTODESK App Store have?
Though a "Show all" button is not provided in Publishers tab, a simple search with blank parameter still return a reasonable result:
publishers available on AUTODESK App Store.
That means, on the average, each publisher owns 3.8 Apps. However, the result seems not up-to-date, or the App number of each publisher is not up-to-date. Also, there are many publishers I haven't ever seen on the Apps page.