Peer-to-peer technologies have became commons nowadays. Initially developed for file sharing, the peer-to-peer approach is moving into the more challenging field of streaming. PPETP is a peer-to-peer streaming protocol, developed at the University of Udine, initially designed for streaming live material to large user communities and evolved with time into an efficient, generic overlay multicast protocol with many built-in features (e.g., signatures, NAT traversal, robustness, priority classes) that make it practical. After few years of development, adjustments and optimizations, PPETP is finally getting ready for its first public release. Its official specs are published as an Internet Draft, while its reference implementation is an open source Ada library (~1.5 Mbyte of source code) designed to be used, in the most common cases, with an interface similar to the well-known BSD socket interface. In this talk, after a brief overview of the most interesting characteristics of PPETP, we will discuss some of the most challenging aspects in its implementation and how Ada was instrumental to solve them.