Is there an open source (or free) service for website prototyping?

Can you be a little more specific? What are you trying to accomplish?

@anon81 Sorry. I know. Not good answers without good explanation.
I'm looking for a frontend tool to create drafts for clients. So I don't want to code just to give them an first impression. Drag and drop or something like that would be finde.

This is like a scene from SO:

- Is there <soft>?

- wild downvote appeared

@KeyWeeUsr Your comment didn't answer my question but it made me laugh :D
Gess "-1" means "no"...

@AndiLeni well, this isn't answer-question place per-se either :P

-1 can also mean "use google", because it's faster than answering btw :)

@KeyWeeUsr Using google is good. Getting information from experienced developers is better. :)