launching a Windows app on client side (triggered by click on webpage)

Question

is that possible to launch a preinstalled application from a webpage.

i can see that steam has created its own protocol steam:// by installing something into my registry and now whenever i click a steam://ip link .. it tries to launch a file. so i was wondering if its possible to launch an application from a webpage, may be register an application to a URL protocol?

example: lets say i have link to a media file on my webpage(lets say divx). now one choice is divx webplayer or other choices. but i want that given a choice the user can launch vlc directly by clicking a link (vlc:// http://...), is that possible?

i read a little about this here but it doesnt clicks clearly to me.

Answer 1

Yes: you would need to build/register a URL handler and tie it to the right application. The simplest explanation is previously answered at How can I add a custom url handler on Windows. Like iTunes itms://.

More complex URL handlers will require you to do native code of your very own: the document you linked to is completely correct. You will need some familiarity with writing registry files, but otherwise it is quite doable.