If you understand one, then you can understand nearly all. http://programphases.com/

My list:
Java - Used mostly for research
Visual FoxPro - Used extensively in the past for building database apps.
C - Used mostly for console based utilities
Visual Basic 6 - research
C++ - research
C# - Use everyday to do Windows/ASP.NET and Sharepoint develoment
VB.NET - research
Mananged C++ - research
Python - research
Perl - research
PHP - Used to manage my web site
Ruby - research
Tcl - research
Delphi - research
Objective-C - research
Ada - research
List - research
ActionScript - research

The research is done for my web site devoted to creating a master index of programming functionality across many different programming languages.

The following information is from the analysis done at the Program Phases site.

Verbose Output of ConvertDays() function:
1980: 366 (10593 - 366 = 10227) years=1
1981: 365 (10227 - 365 = 9862) years=2
1982: 365 (9862 - 365 = 9497) years=3
1983: 365 (9497 - 365 = 9132) years=4
1984: 366 (9132 - 366 = 8766) years=5
1985: 365 (8766 - 365 = 8401) years=6
1986: 365 (8401 - 365 = 8036) years=7
1987: 365 (8036 - 365 = 7671) years=8
1988: 366 (7671 - 366 = 7305) years=9
1989: 365 (7305 - 365 = 6940) years=10
1990: 365 (6940 - 365 = 6575) years=11
1991: 365 (6575 - 365 = 6210) years=12
1992: 366 (6210 - 366 = 5845) years=13
1993: 365 (5844 - 365 = 5479) years=14
1994: 365 (5479 - 365 = 5114) years=15
1995: 365 (5114 - 365 = 4749) years=16
1996: 366 (4749 - 366 = 4383) years=17
1997: 365 (4383 - 365 = 4018) years=18
1998: 365 (4018 - 365 = 3653) years=19
1999: 365 (3653 - 365 = 3288) years=20
2000: 366 (3288 - 366 = 2922) years=21
2001: 365 (2922 - 365 = 2557) years=22
2002: 365 (2557 - 365 = 2192) years=23
2003: 365 (2192 - 365 = 1827) years=24
2004: 366 (1827 - 366 = 1461) years=25
2005: 365 (1461 - 365 = 1096) years=26
2006: 365 (1096 - 365 = 731) years=27
2007: 365 (731 - 365 = 366) years=28 - causes infinite loop
2008: 366 (366 - 366 = 0) -- On last day of leap year, program execution never gets here.

On December 31st 2008, IsLeapyear(2008) is true and days equals 366. If IsLeapYear(2008) is true and days is not greater than 366, the number of days never decrements again resulting in days never becoming less than 366. If the days never becomes less than 366, the infinite looping results.

Analysis of the bug can be found here and verbose loop analysis can be found here.

Complete output from stepping through the faulty loop starting 10593 days from January 1st 1980 can be found here.

I just got done writing and self publishing my first book titled "Program Phases, A Programming Language and API Translator". The book is designed to help programmers learn new programming languages quickly.

I edited the book using Word XP 2002. The way Word renders formatted text is really inconsistent. Fonts changing randomly was really annoying. A page will not render properly unless a print preview is first displayed. I used Adobe Acrobat to convert the word files into a PDF. Acrobat worked really well.

I recommend first determining the page size and margins that are required by your publisher/printer. Create a test chapter and convert to PDF. Try different tools and see what works for you. I did create a small test using OpenOffice and I may use that for my next book.

My book's web site is located here: programphases.com