best pdf api in java
i have started working on some application that requires pdf manipulation and form filling.
i got to know about different available apis -
active pdf ,dynamic pdf , fdf merge(utility) and iText.

I want to know which one is best .
my application requies 
PDF forms filing and manipulating.
We dont have much graphics involved but some event handler buttons with javascript behind it.Text fields, checkboxes,combolists and many hidden fields.
i know except iText others are licensed.

Thanks.

best pdf api in java
===

i have started working on some application that requires pdf manipulation and form filling.
i got to know about different available apis -
active pdf ,dynamic pdf , fdf merge(utility) and iText.

I want to know which one is best .
my application requies 
PDF forms filing and manipulating.
We dont have much graphics involved but some event handler buttons with javascript behind it.Text fields, checkboxes,combolists and many hidden fields.
i know except iText others are licensed.

Thanks.
