3.4. Hang on, isn't Forth out of date now?
One of the best answers came from Brad Rodriguez <mailto:firstname.lastname@example.org>. You can find the full version at <http://www.complang.tuwien.ac.at/forth/faq/why-forth>. In short, Forth's advantages are that it's comprehensible, small, interactive, fast, extensible, and makes it easy to work at a high level of abstraction.
BTW, this question came from someone comparing a 10+ year old Forth system with the latest version of Borland C++. His system was really out of date, but also with respect to current Forth systems.
3.5. Is Forth faster or smaller than C?
Not in itself. I.e., if you translate a C program literally into Forth, you will see a slow-down (e.g., a factor 4-8 with Gforth, a threaded-code system; for typical native-code systems you will see a factor of 1-3). Similarly, there is no inherent size advantage in Forth. For details see <http://www.complang.tuwien.ac.at/forth/performance.html>.
However, there are many reports of cases where Forth programs beat others in size and/or speed. My guess is that the added flexibility of Forth helps programmers produce faster and/or smaller programs.
3.6. What language standards exist for Forth?
An American National Standard for Forth, ANSI X3.215-1994, is accepted worldwide as the definitive Forth standard ("ANS Forth"). This standard also has been blessed as international standard (ISO/IEC 15145:1997).