In April 2009 I was invited to speak on FreeBSD/PmcTools by the Bangalore chapter of the ACM. The slides for this talk are available at: http://people.freebsd.org/~jkoshy/download/acm-apr-09.pdf (550KB, PDF).
This was an overview talk. The talk briefly touched upon: the motivations and goals of the project, the programming APIs, some aspects of the implementation and on possible future work.