Wired:What does it mean when somebody takes your hard work and builds on it for free? In the normal business world, that would be the beginnings of a lawsuit, writes Danny O'Brien.

On the internet, it's a sign for a sigh of relief. When someone else uses your creation for their own business, you're one step farther away from being an also-ran, and one step closer to being an irreplaceable fixture on the internet.

An example from this week: the announcement of Open Komodo, an open-source application based on the Mozilla suite of browser code.

Komodo comes from ActiveState, a company whose core commercial products depend on the open-source Mozilla code for their basic functions. To build your business on Mozilla is a show of confidence in Mozilla's longevity. Mozilla, as the saying has it, is a stable platform.

Marc Andreessen, the man behind Mozilla's ancestor, the Netscape browser, knows a lot about platforms. He's been building them since the first rash claims that his Netscape browser would replace Windows as the future internet operating system.

Now platforms have humbler aims: Andreessen's latest platform, Ning, just wants to be the basis for coders building social-networking sites. Even Mozilla, which once had dreams of being a platform for any desktop application coder, has humbler aims. Still, becoming the platform is where most internet entrepreneurs would like to end up. At least here in Silicon Valley, it is.

Creating a platform from your software is one of those strategies that works well in Silicon Valley but is far harder to kickstart elsewhere.

Developers rave about their pet project in bars here; someone in on the same round of drinks hacks together support for the product the next morning. Still, I've listened to plenty of well-regarded advocates bend my ear over a world-changing approach that has failed to catch fire, even when supported by all the right digerati. But when they do take off, they take off with all the hype of a dotcom bubble balloon. The latest example is Facebook, which has become a platform by dint of letting others play in its sandbox. You can write an application that will run within Facebook, and then use the data that millions of users have fed into it.

Commentators have suggested that Facebook is the new internet: that programmers will flock to work within it because the information they can use is richer than if they lived outside Facebook.

This is unlikely, however. The lesson most developers have learnt is that, if you're working within a platform that's owned by someone else, you're a slave to their whims.

It's one of the reasons for the rise and rise of open source. At the very least, if a company driving an open-source solution goes bust or psychotic, you can "fork" the code - take it and run in another direction.

That's a good reason to place more trust in companies like ActiveState: if the Mozilla Corporation dies or takes a wrong turn, the Open Komodo developers can continue to adapt the Mozilla platform to their own needs.

By contrast, a fully-owned platform like Facebook is a bomb waiting to go off. It's a fine place to build toy applications, as many firms are doing, but you wouldn't want to - and couldn't - live there.

The trick in the internet age is to use a platform that you can walk away from. Coders in the age of the desktop used to try this by attempting to write code that would run with minimal changes on Windows, Mac and whatever other platform was around. It didn't work, because Microsoft kept giving bigger and better rewards to those who committed to living within its ecosystem. Any application not taking advantage of the latest Windows-only glitter looked pale in comparison.

But coders remember when Bill Gates really did walk off with their ideas, building them for free into the core operating system and putting them out of a job. Now smart coders only work on platforms that don't incarcerate them. The attractions of Facebook notwithstanding, it'll be those who walk away who will last this boom out.