IBM FileNet eForms Designer is a powerful form designer tool which runs on the client side to connect to BPM  or ECM

if you want to do , you can use following topics with eForms

Automatic calculations

Data validations

Data validations with external jsp page

Database access with  JDBC , ODBC , HTTP or external jsp pages

Data submission to business process  

Integrate content engine with Workplace configuration

Develop javascript code with javascript api