Most software is made by programmers creating text files that are fed to a compiler and loader which makes a runable program. One can tell how early- or late-bound a system is by looking at the things that can be changed while the program is running. For example, it is generally true of C based systems that most changes in the program have to be done by going back to the text files, changing them, and recompiling and loading them. This is even true of Java. Organizationally, this often leads to at most one or two system builds a day before most bugs can be found.
A late-bound system like LISP or Smalltalk can change pretty much everything while it is running -- in fact, both these systems are so good at this that their development systems are written in themselves and are active during runtime. For example, a program change in Smalltalk takes less than a second to take effect, thus many more bugs can be run down and fixed.
But late-bound has some deeper and more profound properties that include abilities to actually change the both the structure and metastructure of the language itself. Thus an important new idea can be assimilated into the constantly evolving process that is the system.
Another aspect of late-binding is the ability to change one's mind about already instantiated structures that are already doing work. These can be changed automatically on the fly without harming the work they are already doing.
Etc. Wheels within wheels.
These ideas are not new, but they are quite foreign and out of the scope of the way most programming is done today. -- Alan Kay.
To summarize - you want a system with no downtime? Use Smalltalk. You want a system that has to be taken down and up every time you make even a small change? Go ahead, use one of the "analyst approved" mainstream systems. I'll be over here, being productive...
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