Freeware and OpenSource Pt.2

A pretty large chunk number of applications are use daily are opensource applications. A list I'll try to keep up to date is here.

Being an active user of opensource software, being a not-so-active contributor so open source projects (I've submitted a few patches to some projects), and even having a project on SourceForge, I've been putting a little bit of thought into what starts and keeps OpenSource software going.

There a few reasons that I can think of:

• Brand new software with no real commercial alternative, designed to be used by itself - There a lot of applications like this. I think most of these are smaller projects, utility applications, etc... - WinDirStat, SysInternal utilities, etc...
• Applications created to support commercial products - NUnit, NDoc
• Free, Open Source alternatives to commercial applications - NSIS, Subversion, QuickFix
• Commercial Products released under Open Source - OpenOffice

The reasons above can be split into two categories: Projects that have commercial backing and products that don't. So the question I'd like to raise is how long will projects without commercial backing survive, and what will be the reason for survivor or their demise. Will they survive when corporations will put their resources to create commercial product against a free alternative. I've noticed the same questions asked by others to the project coordinators as well.
NUnit - "The Death of NUnit Revisited"
NDoc - "NDoc 2 is Officially Dead"
Considering how fierce is the competition between comercial products, will the OpenSource projects that are developed by some great developers during their spair time using their own resources, be able to stand up to the competition? Or will the projects live only as long as they are not good enough to be considered a competition by the coorporations, and die as soon as they become a threat (or atleast a competition)?

Freeware and OpenSource Pt.2