TOAD (Tool for Oracle Application Developers) ,The most popular of all the PL/SQL IDEs, TOAD is famous for its tabbed browser and "Swiss Army Knife" approach. Available in both commercial and freeware versions.
SQL Navigator ,Also from Quest, this IDE has been around a long time—and it shows in the depth of its
support for PL/SQL and Java programming in the database.
PL/SQL Developer ttp://www.allroundautomations.nl/plsqldev.html,A fine and relatively inexpensive entry from the Netherlands, PL/SQL Developer offers a large number of features in a very nicely designed package. It also allows third-party developers to provide plug-ins to extend the base product's functionality.
TOra (Toolkit for Oracle) ,This toolkit includes a browser, PL/SQL editor, and debugger for Linux or Microsoft
Windows. TOra is available in open source and commercial forms.