RTF. I finally found my time to work on RTF filter for KWord. Looks really good and useful to give me more insight about document formats.
Quenya. Well, it's just amazing. Sadly enough I do really lack of time to learn it.
English isn't easy. Anyhow, good that I still can reach a score of 606 in my recent TOEFL. I'll be very happy if someday I could ever know Quenya as good as English :-P