Digital fountains have changed the standard transmission paradigm. A digital fountain can encode and transmit an unlimited number of data packets until every user gets enough information to guarantee correct decoding. Multimedia broadcasting, emerging peer-to-peer applications are only two examples of many other scenarios where digital fountains can be successfully applied. In this paper practical implementation issues of two class of digital fountain codes, namely LT and Raptor codes, are analyzed. Moreover, the performance in terms of coding and decoding complexity is measured experimentally.