I've conducted a trademark search at the USPTO (US Patent and Trademark Office) and got the following LIVE trademarks. The only one that is remotely conflicting IMO is the "WICKETS NTS" trademark. However, it is "wicket_S_" and "NTS".
I think the "Apache Wicket" name should be fine. Word Mark WICKETS NTS Goods and Services IC 009. US 021 023 026 036 038. G & S: ENCODED TAGS, CARDS, CHIPS, TOKENS AND BADGES AND READERS FOR USE THEREWITH; CENTRAL PROCESSING UNITS, COMMUNICATION SERVERS, COMPUTER HARDWARE, COMPUTER HARDWARE FOR TELECOMMUNICATIONS, COMPUTER MEMORY HARDWARE, COMPUTER NETWORKING HARDWARE, AND COMPUTER HARDWARE AND COMPUTER SOFTWARE PROGRAMS FOR THE INTEGRATION AND INTERACTIVE DELIVERY OF INFORMATION BETWEEN GAMING MACHINES AND TABLES AND A NETWORK SERVER CONTAINING PLAYER ACCOUNT INFORMATION, PLAYER TRACKING INFORMATION AND PLAYER ACCOUNT BALANCES FOR CASHLESS WAGERING, REDEMPTION AND SERVICE TIPPING Standard Characters Claimed Mark Drawing Code (4) STANDARD CHARACTER MARK Serial Number 76669340 Filing Date November 21, 2006 Word Mark WICKET MAN Goods and Services IC 028. US 022 023 038 050. G & S: line of croquet components, namely wickets, stakes, mallets, balls and carrying cases. FIRST USE: 20050101. FIRST USE IN COMMERCE: 20050101 Serial Number 76582889 Filing Date March 23, 2004 Word Mark WICKETS Goods and Services IC 004. US 001 006 015. G & S: Candles. FIRST USE: 20011000. FIRST USE IN COMMERCE: 20011000 Mark Drawing Code (1) TYPED DRAWING Serial Number 76323419 Filing Date October 10, 2001 Word Mark LILLY WICKET Goods and Services IC 025. US 022 039. G & S: Women's clothing, namely, lingerie, undergarments, hosiery, and sleepwear. FIRST USE: 19980201. FIRST USE IN COMMERCE: 19980201 Mark Drawing Code (1) TYPED DRAWING Serial Number 75370728 Filing Date October 9, 1997 Word Mark WICKET'S WAFFLES Goods and Services IC 031. US 001 046. G & S: dog biscuits. FIRST USE: 19921202. FIRST USE IN COMMERCE: 19921209 Mark Drawing Code (1) TYPED DRAWING Serial Number 74561087 Filing Date August 15, 1994 Word Mark STICKY WICKET Goods and Services IC 021. US 002. G & S: lint remover rollers and refills therefor. FIRST USE: 19771221. FIRST USE IN COMMERCE: 19771221 Mark Drawing Code (1) TYPED DRAWING Serial Number 74461550 Filing Date November 12, 1993 Word Mark WICKETS Goods and Services IC 042. US 100. G & S: RESTAURANT SERVICES. FIRST USE: 19630924. FIRST USE IN COMMERCE: 19630924 Mark Drawing Code (1) TYPED DRAWING Design Search Code Serial Number 72289623 Filing Date January 25, 1968 -- Learn Wicket at ApacheCon Europe: http://apachecon.com Join the wicket community at irc.freenode.net: ##wicket Wicket 1.2.5 will keep your server alive. Download Wicket now! http://wicketframework.org
