Lucene.Net should support the Compact Framework & Silverlight versions of the .NET Framework.
I've looked into what it might take to do this and most of it is pretty trivial to be able to support these frameworks. Most of what this would take is just changing the different type of classes to use for collection classes used inside of Lucene.Net.
This does require changing some details in a lot of places, However this should not bring any compatibility issues with Java Lucene's API or index format. It will just change the classes used to some different ones that the frameworks support and also maybe need 1 to 3 classes that might need to be implemented in Lucene.net itself.
Having made these changes Lucene.Net can be more available to new devices such as running on a window mobile cell phone, or your pda, or run in a Windows, Linux, or Mac computer that runs a silverlight application. This will allow the .Net compact framework & silverlight developers to use Lucene.Net in their applications to provide their users with the same capabilities of an awesome search framework. Developers can also use Lucene.Net to provide them spell checking capabilities in these environments.