wt_spamshield is a passive anti-spam extension for TYPO3 forms and works without annoying captchas.
The current development of wt_spamshield is done by TRITUM ( www.tritum.de). The coding is done by Ralf Zimmermann ( firstname.lastname@example.org ) and the documentation and communication lies in the hands of Björn Jacob ( email@example.com ).
The extension was initially created by Alexander Kellner. This great guy is the CEO of in2code ( www.in2code.de ) and maintained wt_spamshield till version 0.8.0.
You can download the current master (TER version) and some dev versions from via https://code.tritum.de/typo3_tritum/wt_spamshield.