I would like to have a complete list of UNIX and Windows applications
exists today? From this list, how many are freeware, shareware,
commercial and enterprise products? What is the total count of UNIX
and Windows applications?

ameau...

I would submit that there is no such thing as a complete
list of programs, since freeware and shareware programs
appear on a daily basis, in various languages, around the 
world. It is unlikely anyone has found a way to compile
anywhere near a complete list, as the task is Herculean
without some central registry through which every program
must pass. To my knowledge, this doesn't exist, nor is it
likely ever to occur.

I would also submit that this task would be quite impossible.  If
anyone can claim to give you a complete list, they are lying.  There
are many dead projects (ie no longer in development), many projects
that are niche and very rarely used, programs that are only used among
a small group of people, etc.  There are some central repositories for
lots of software, including Freshmeat.net, Download.com, Tucows.com,
etc, and they would have links to many, many pieces of software, but
they would not even begin to scratch the surface of what is actually
available in some capacity.

It sounds like you are trying to find statistics for some type of
Report or Paper on the two technologies. If that is true, why not
consider narrowing the scope of your search to the number of programs
available from a particular chain of stores, or even from a selection
of stores in your area. Then you should be able to conduct that
research easily on your own accord

Only google can tell you but there is no way to be accurrate 100%
because programs can be easily created. Not to mention many programs
that are secret ( as in corporations, governments, banks, et. al.)

Wish there was a better answer -- to get close consider visiting
download.com but this is really unanswerable. What if I create
programs at home but do not tell you or anyone else about it? The
program still exists but is not counted... Not too mention all of the
hackers who have Trojan Horses.

One possible solution is to develop a screensaver that enumerates all
the executables on a machine and forwards them to a centralized
location. There are tons of legal and privacy barriers to implementing
this...

The table of equivalents / replacements / analogs of Windows software in Linux.
Last update: 16.07.2003.

http://www.linuxshop.ru/linuxbegin/win-lin-soft-en/table.shtml