Utku,
I am planning to use Oracle's official PL/SQL reference to create an antlr grammar for PL/SQL. However, I am not sure if this would have legal implications.
Is it legal to use Oracle's official PL/SQL reference to create an antlr grammar for PL/SQL?
I'm not a lawyer, so take my advice with care, however I see no reason why you cannot create your own grammar from a public spec. One of the reasons it is public is that it allows to create parsers for it.