My area of interest is broadly defined kernel development. In the spring of 2013 I implemented ASLR and DEP which caused minor confusion due to "activation" of bugs that have been hidden but I think that overall it worked out well for Haiku. Later I tinkered a bit with RTM (Restricted Transactional Memory), new extension introduced in Haswells but the code will need a lot of work before it will become usable. From October to mid-January, I was employed by Haiku, Inc. to work on the scheduler and adaptating Haiku for work on systems with more than one logical processor. Among other things, I got rid of the 8 processors limit, which was quite firmly rooted in the ABI inherited from BeOS.
Great interview with a low-level Haiku developer.