A while ago, I've started to create a complete list of lens makers (current and historical) but restricted to Europe-based ones. I wanted to do this in a forum initially, but since barely any forum allows for unlimited edits (which would be necessary in order to keep the initial post up to dayte), I've decided to try again instead on my own small website and expand it to lens manufacturers from all over the world. Here's the current list:
www.simplejoy.at/articles/list-of-lens-makers/
During the last couple of weeks I've been able to add a good number of manufacturers from the other continents, but I'm sure that I'm still missing an incredible amount of them, particularly from China, Japan and likely lots of smaller ones from the US and probably a couple of countries, I haven't considered.
The current definition for the list is the following: "manufacturers of all kinds of lenses related to photography, including industrial, enlarging and projection lenses but not single components or lens elements for glasses, binoculars etc."
So if you spot any lens maker, however small - I'd really appreciate it, if you could let me know about it!