Component Object Model Examples?

Hello all, sorry to throw a dumb question out on the table. I've been doing some looking up on COM and looking at what all the business is with it. Funny enough even though I've been programming for such a long time this is the first time I've actually looked at what COM is and what it could do for me. I've looked at msdn, and a few websites talking about this, but I still kinda don't know 100% how I could use it.

From what I've seen or looked on here it only looks like a way of transferring data from one application to another, like ActiveX and Internet Explorer. To me it kinda seems like one of those things I have no use for, since I write basic programs and game engines sometimes using the stander libraries. I think I some how maybe missing the point.

I was wondering if someone could give me better examples what it's used for and why I should use it. It seems like the only useful thing I had it doing is creating a shortcut on my desktop, but I don't think that's even half of what it could do. I do want to expand my programming vocabulary and try to learn much about COM as possible.

Thanks, Ajm.
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COM ha been known under so many names already, it's not even funny: OLE, Network OLE, COM, DCOM, COM+, ActiveX (and all of the names I forgot) are basically just what is known as COM in one way or another.

The first thing you need to know is that COM is not a library, it's a method of writing and consuming libraries.

Do you have Visual Studio? To get a quick taste of using COM libraries, create a new empty C# project. Right click "references" in the solution explorer. In the dialog that pops up, select COM. You now see a list of all COM libraries that you have intalled. Select the one you want to use, and presto, you now have access to all the objects in that library.

To make a COM component yourself in C# that others can use, googling "ComVisible" should take you a long way.

What can this be used for in games? Well, extensions of course.

Want to make a plugin system? Define a COM interface that the plugin must implement. As a bonus, you can even make the plugin run in another addres space, so it doesn't take your game with you when it crashes.

You can also have parts of your game exposed as a COM API that can be accessed from the outside, or perhaps from inside the plugins that your COM plugin system loads ;)

Wow, thats pretty cool, so then it's kinda just like a plugin or a tab in Google Chrome, if a page or a plugin crashes, it wont crash Chrome it's self. =)

Hey I could actually maybe use this technique, for future projects then, if it may means less frustration in the future for my users I don't see why not to learn it then.
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My opinion is that everyone who is a windows programmer should learn at least something about COM, otherwise they are missing out on a great tool, and also a big part of the Windows software ecosystem. Unfortunately, it isn't easy to find a great overview that explains it all in an understandable manner, which leads them to just ignore it and say that it's been replaced by [insert non-related tech here].

I actually use C++ as my main language so I may play around with it more in C++, but I don't see why not to use C# just for fun.
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I will (probably tomorrow) try to gather some links to examples of COM usage. It's probably easier to begin with C# examples, as it is much clearer what is being accomplished without all the confusing stuff you need to do in C++, but I will attempt to find good C++ examples also.

Just a quick question, if say my main program crashes I guest the plugins would go down as well. I was thinking it could be used to detect if a program crashes.
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Well, I guess it's possible. If you are using an object from an outproc server (which could be your main application), the client would receive a RPC_E_SERVERFAULT if the main application crashes. But I would not use it in that way.