Any ActiveX processing calls can only be made from JScript running on Internet Explorer because ActiveX is only accessible from that browser (one of Microsoft's mistakes given the huge number of security holes that access created that they then had to plug).
As these commands can only be used by Internet Explorer their usefulness is limited for pages that are going to be placed on the web. These commands will only be properly usable on the web where JavaScript provides an equivalent way of achieving the same result which in most cases there is no equivalent.
The only instance I can think of offhand where there is a JavaScript equivalent is with the XMLHttpRequest object available in JavaScript (and Jscript from version 5.8 onward) where an ActiveX call makes the facility available in older versions of IE.
With the exception of using ActiveX calls that are the equivalent of JavaScript commands that JScript doesn't support there is no real point in attempting to use ActiveX in your web pages at all since doing so will mean that your page will only be fully functional for those of your visitors using IE and not by the majority of your visitors who are using other browsers. The security issues that using ActiveX in a web page raise are such that IE7 and later may not allow your ActiveX to run anyway making its inclusion even more pointless.
Anyone with any security knowledge who for some reason has been forced to continue to use IE6 will have disabled ActiveX in order to plug all the security holes that can't be plugged any other way without upgrading to IE7 (and will therefore have active scripting disabled as well to get rid of all the alerts about ActiveX being disabled). This makes including ActiveX specifically for IE6 and earlier users somewhat pointless as well since with security set correctly they will not be run.
None of these factors should really affect the way that you use ActiveX anyway since that option was not included in Internet Explorer so that it could be used on the web in the first place. You are not supposed to be using most of the ActiveX calls on the web at all. ActiveX was included in Internet Explorer so that it can be used for intranet sites so as to allow the staff within a company to be able to interact more easily with the staff only section of their company web site and its use for that purpose is quite practical since the people writing the web pages for the intranet know exactly which browser version will be used to access the pages and how the computers accessing it will be configured. Also those pages will be configured to run in the trusted zone rather than the internet zone allowing the company to allow the ActiveX controls on their pages to work while denying pages on the internet from using the same controls.
Unless you are creating web pages for your company intranet the only time you need worry about ActiveX controls in your J(ava)Script at all is if you decide to include the ones that serve as the equivalent to JavaScript commands that only have an ActiveX equivalent in JScript. If your code uses ActiveX and works only in IE then there is little point in asking how to get other browsers to perform the same processing since chances are that other browsers will have no equivalent way of doing it and the code that you think works in IE will only work for some IE users anyway.
Note that I have heard of ways of adding ActiveX support to other browsers but since it has to be done with the browser owner and ActiveX is well known for its security issues you can't really expect your visitors to install it even if they are running a browser that supports its installation.
