How to start an exe or a program on client machine from browser.

I am creating a website which provides the facility to the users to edit their documents without downloading them, so for that i created a exe which do this work.

My requirement is how can I open my already installed program or exe on client machine from browser. (Like apple site runs itune on client machine)

I tried with ActiveX in javascript but that is also not working. It is giving error that object can't be created.

I also tried with using the batch file but in i.e. it gives the option to run directly but in firefox and chrome it is first downloading and then user can start it.

I had heared about protocol handler, but don't know anything about this.

Can anyone help me out with some code or some helpful link.

Thanks.