General talk about software patterns

[Ralph Johnson <johnson AT cs.uiuc.edu>]

The only way to know for sure which patterns are used most is to
look at every system in the world.  Some people use some patterns
more than other people do, so if you just look at the output of one
group or one person, you will get a different answer dependig on
who you talk to.

The most commonly used pattern is Template Method.  That is because
a singple class can use it a dozen times, and because nearly all
abstract classes in well designed systems have them.  C++ programmers
often think of abstract base classes like Java programmers think of
interfaces, but in Java, there is no reason for abstract classes not
to have template methods.

Singleton is popular, but it is one of the most misused of all the 
patterns.  If it is the third most popular design pattern in your
systems then your systems probably have problems.

-Ralph Johnson