You must be registered to be to participate in forums.
Please click on "(Register)" in the very upper right corner of the screen. After following the instructions your login name will be shown (normally it looks like my.email.name.x) and you will receive an automatically generated e-mail with your password (don't forget to check your Spam/Junk folder!). Normally you can sign in as soon as you receive the e-mail. Occasionally you have to wait, sometimes even more than 15 minutes, before you can sign in.
Download source code
Go to Download in the menu bar and select 'source code'. Just follow the steps as indicated.
Consult the forum
If your questions are not answered satisfactory in the RTC-Tools manual; check out the forum for help.
If you still have not found what you were looking for you might be interested in purchasing professional support. Please contact Deltares for details.