Saul Candib, our technical writer for Visio, has posted an excellent article on MSDN explaining how to publish Visio 2007 solutions. In this context "solutions" refers to the add-ons, templates, stencils and/or help files that you have created and want to distribute to other people.
We covered this topic in a previous post, but the MSDN article goes into greater depth. Saul describes the basic options of using path discovery (the classic way Visio content is found and usable in the application) or publishing content using Windows Installer (the method introduced in Visio 2003). There is a good summary of the benefits of using Windows Installer, which is repeated here:
By publishing content, you can better integrate it into Visio. For example, you can more easily control the location of menu commands that start your solution or open your stencils, how the commands are named, and when they are available to users.
By publishing content, you can more easily publish localized versions of your solutions together with the Windows Multilingual User Interface Pack (MUI). (The MUI is a set of language-specific resource files that allow the user interface language to be changed, according to the preferences of individual users, to one of the 33 supported languages.)
Published content offers better performance, because published information is stored in the registry, where it can be retrieved more rapidly.
The Windows Installer Setup wizard is familiar to users and easy to use.
By publishing content, you benefit from Windows Installer repair and add-and-remove software features.
Publishing your content makes it available to all users of computers with multiple users. Path discovery works only for individual users.
The bulk of the article explains in detail how to do publishing with Windows Installer. There are a number of steps and tools involved, so you should find this write-up quite valuable. The article is written for Visio 2007, but much of the information is applicable to Visio 2003.