Seamless is a reflective communication middleware for Pharo that aims to facilitate the prototyping of distributed applications. It provides developer friendly abstractions and syntactic sugar for an out-of-the-box Pharo to Pharo communication experience. After prototyping your application, Seamless lets you easily profile and tweak communication settings such as distribution and serialization policies for optimizing performance and avoid common distribution caveats. This Chapter covers version 0.4 of Seamless for Pharo 3.0 and will be updated frequently towards version 1.0 (stable release).