In Web 2.0? Try 3.0, Dan Gillmor asks:
If the web is becoming an operating system in its own right, can anyone monopolise it the way Microsoft did on personal computers? As long as the webâs basic functions remain open, the threat is more theoretical than real.
I think the threat of monopolisation of the web as an application platform is very limited. One of the key aspects of the move towards web services is that anyone can make services available, and the formats are open because they need to be - if they're not open you'll see limited use.
The one possibility for Microsoft or someone else is to build tools that provide a killer app for interaction between sites in a proprietary way and make them widespread enough to become "required". However given Microsofts failure to get even Passport to become widespread I think the risk of this is low.
Particularly given the ease of duplication. It is extremely hard to create a compelling service on the web that can't be duplicated easily. The only real barriers you have are copyrights on content (you could think about patents, but in general patents are usually possible to work around) and brand loyalty of an existing userbase.
Neither of these are likely to be significant obstacles in the same way as Microsofts' near monopoly on Office applications have been for instance.
The one area that is a bit worrying is video and audio content with DRM, but recent events have demonstrated quite clearly that DRM in general is easily breakable and only a barrier to people that have "acceptable" alternatives that removes the incentive for them to spend time on digging up tools to break the protection.
As long as we are vigilant about fighting any attempts to take away our ability to break DRM through legislation I think we'll be just fine. But even with a repressive legal environment DRM will continue to get broken as quickly as new schemes are created.
But for other types of web services we also need to remember that it is in a service's best interest to be available to as many people as possible - unless a proprietary solution truly offers massive advantages it is unlikely to ever get traction. Locking out a few percent of the userbase can be enough to eradicate your operating margins and give your competition the advantage they need to demolish your business.
Microsoft were able to establish their monopoly in large part because they did not have an organized opposition from any large movement strongly focused on open standards. Any proprietary service provider attempting something similar today will have to except strong opposition.
Consider for instance the cases of del.icio.us vs. de.lirio.us or the recent Bitkeeper mess as examples of what kind of reaction you're likely to face if your attempts at lock in online gets too serious (Bitkeeper) or even just don't release the source (del.icio.us) to a service seen as important by the open source community.