I'm happy to announce that in the on-going development towards OpenNeL 0.6.0 we have successfully eliminated the STLport requirement. If you are working with SVN trunk on Windows please be sure to remove the STLport include directories from your VC Project Directories. There is still some work to be done around some STLport-specific optimizations within the particle system allocation and point light allocation but otherwise all important tools and samples have been tested successfully excluding any pre-existing problems.
Please report on JIRA immediately any problems you encounter with SVN trunk as they may be related and we want to aggressively attack all bugs so that we can increase the quality of the next release!
Thanks to everyone who participated in the effort to eliminate STLport from our requirements list.