From their website:
libLAS provides excellent coverage of the ASPRS LAS 1.0 and 1.1 specifications, and it provides support for copying variable length records from one file to another. As of 1.0.0-beta-1, support for creating your own variable length records is limited to the C and C++ APIs. libLAS concentrates on reading and writing point data for processing pipelines from C++, C, and Python.
The beta version of 1.0 supports creating any of the vector formats supported by OGR. This makes it all the easier for open source users to handle LiDAR data.