Brad seems to think this is a problem with open source software: if the programmer disappears the you are in trouble. But there are two kinds of open source software: software which simply makes the source available, and free software, as in the GNU, BSD or MIT licenses. In the case of free software, anyone, without permission of the owner, can pick up the project. This provides some insurance against the disappearance of the original owner. In the case of software that is nonfree - whether or not it is open source - if rights for further development cannot be negotiated with the original owner, either because he/she is unwilling, or simply can't be found, there is no legal modification of the software that can take place - and then you really are in trouble.
The most widely used open source software - Linux, Apache and Mysql - are free software. The widely used PHP program is (in its current version) open source but not free. Java is neither open source nor free.
One of the goals of the Creative Commons License is to make sure that copyrighted material does not become unavailable or unusable if the owner abandons it; Larry Lessig's proposal to once again require copyright renewal is designed to serve the same purpose. Changes in copyright law that have made copyright automatic and eliminated renewal create an enormous problem with abandoment, because unless the owner makes explicit provisions, abandoned creations become unusable by anyone. Unfortunately, these modifications of the copyright law serve no useful economic purpose - it appears in fact that they are designed to protect large businesses which can cover the fixed cost of finding and negotiating copyrights from competition from small businesses that cannot.
