In this paper, we present SL Teacher, a framework for teaching French sign language using web 2.0 and virtual signer technologies. We present here the main features of the web-based framework that supports the sign lexicon animation and the dynamic sign language utterances generation. We discuss the tradeoffs and the ensuing simplifications applied in order to insure a good level of interactivity with the users in the low bandwidth context of web systems. We present the symbolic representation of the sign language utterances and the associated construction procedure. Finally the implementation, accessible on the web, is illustrated here with an example of a simple teaching task that requires all the features of the SL Teacher framework.