Useful Links

• HKOI Judge - Programming exercises and real-time judge (for HKOI trainees only)
  http://judge.hkoi.org
  
  
• HKOI Contest System - Programming exercises and real-time contests (for HKOI trainees only)
  http://contest.hkoi.org
  
  
• HKOI Official Homepage
  http://www.hkoi.org
  
  
• HKOI Newsgroup - Announcements and discussions on OI issues
  news://news.hkoi.org/hkoi
  Web interface: http://news.hkoi.org
  
  
• FreePascal - Pascal compiler used in IOI, NOI and in HKOI training
  http://www.freepascal.org
  
  
• International Olympiad in Informatics
  http://olympiads.win.tue.nl/ioi
  
  
• USACO Training Program Gateway - An excellent source of OI-style programming tasks http://train.usaco.org/usacogate
  
  
• Olympiad in Informatics Beginners' Home - OI materials by students in Mainland China (Simplified Chinese)
  http://oibh.ioiforum.org
  (Note that these "beginner" materials may be quite difficult)
  
  
• ACM Problem Set Archive
  http://acm.uva.es