How to launch an application from a browser?

Is it possible to launch an application from a browser? I am not talking about opening a file from a browser (like open a PDF with Adobe Reader), but rather opening a new (blank) instance of an application that is installed on the user's machine.

Hypothetical situation: User browses a website that lists computers that can be managed via RDP. He clicks on a link to 192.168.1.10, that link opens Microsoft RDP client (mstsc.exe) with that ip address already filled out.

I am talking strictly about Windows universe.

Is that thing even doable outside of ActiveX and IE?

Is it wise to attempt this in IE with ActiveX?

The correct method is to register your custom URL Protocol in windows registry as follows:

[HKEY_CLASSES_ROOT\customurl]
@="Description here"
"URL Protocol"=""

[HKEY_CLASSES_ROOT\customurl\shell]

[HKEY_CLASSES_ROOT\customurl\shell\open]

[HKEY_CLASSES_ROOT\customurl\shell\open\command]
@="\"C:\\Path To Your EXE\\ExeName.exe\" \"%1\""

Once the above keys and values are added, from the web page, just call "customurl:\\parameter1=xxx¶meter2=xxx" . You will receive the entire url as the argument in exe, which you need to process inside your exe. Change 'customurl' with the text of your choice.

You can't really "launch an application" in the true sense. You can as you indicated ask the user to open a document (ie a PDF) and windows will attempt to use the default app for that file type. Many applications have a way to do this.

For example you can save RDP connections as a .rdp file. Putting a link on your site to something like this should allow the user to launch right into an RDP session:

<a href="MyServer1.rdp">Server 1</a>

Some applications launches themselves by protocols. like itunes with "itms://" links. I don't know however how you can register that with windows.

@AbhijithCR 's reply works well. To register the protocol via a .bat file, do something like this

set key=customurl 
reg add HKCR\%key% /ve /d "URL:Description" 
reg add HKCR\%key% /v "URL Protocol" /d "" 
reg add HKCR\%key%\shell 
reg add HKCR\%key%\shell\open 
reg add HKCR\%key%\shell\open\command /ve /d ""c:\path to\your.exe" ""%%1"""

For me getting all the quotes and the double percent signs right was the tricky part.

We use a sonicwall vpn. It launches a java applet that launches mstc with all the credentials setup. You really can't do this without a java applet or activex plugin.

Microsoft uses this technique itself on their small business server for getting inside the network. I wouldn't say it is a terrible idea, as long as platform independence isn't important.

You can use SilverLight to launch an application from the browser (this will work only on IE and Firefox, newer versions of chrome don't support this)

Example code here

I achieved the same thing using a local web server and PHP. I used a script containing shell_exec to launch an application locally.

Alternatively, you could do something like this:

<a href="file://C:/Windows/notepad.exe">Notepad</a>