Why not just use macros? You can get pretty close to BASIC's syntax and commands with nothing but assembler macros...

http://www.purebasic.com

purebasic backend is FASM.
It is Available on windows, linux.

PS: Personally i prefer c, not basic.

The problem here is that BASIC requires a pretty large library of functions. Implementing a parser/converter for the language isn't a problem. Writing the library code is.

You're right that FreeBSD and Linux are different from a programmer's perspective. But they aren't that different. It's easy to adapt an assembly program for Linux to run on FreeBSD. Look at asmutils (written in nasm, but the principle applies) which can be reassembled for various OSes with minor changes.

You still run into translation problems: you'd have to convert BASIC into a subset of C, then call the C libraries. This is because C libraries are not compatible cleanly with the BASIC way of doing things.

you do all the translation in the compiler from the point of view of there is
nothing but basic

the c libraries are so low level that it dosen't matter what lanuage you use to call them

as a short cut you could work on a front end to gcc and have gcc do most of the work for you
as a fact of the matter fortran is so close to basic that it woulden't tack much to change it's front end to compile basic

or learn fortran most of what you already know about basic applys to fortran
some of the key words differ but the style and syntax are the same

C     Hello World in Fortran

      PROGRAM HELLO
      WRITE (*,100)
      STOP
  100 FORMAT (' Hello World! ' /)
      END
    

       PROGRAM HELLO
c
C      Hello World in Fortran IV (supposedly for a TR440)
c
       WRITE (6,'('' Hello World!'')')
       END    

C     Hello World in Fortran 77

      PROGRAM HELLO
      PRINT*, 'Hello World!'
      END    

fourth is about the olny major programming lanuage there is and there is even a
gnu version that uses the standard c libs

GNU fortran is an ansi77 fortran so there's not that much red tape
I would love to learn forth the big problem I'm haveing is that there is no
forth system that matches any of the documentation I can find and who ever writes
a forth interpter dosen't do tutorials for there forth

Code:

C     Hello World in Fortran

      PROGRAM HELLO
      WRITE (*,100)
      STOP
  100 FORMAT (' Hello World! ' /)
      END
    

...

Fortran has quite a bit more red tape than BASIC from what I've seen of it in the examples I looked at. Even simple things like "Hello World" involve more typing a bit more red tape than BASIC does.

| Hello world in Forth
." Hello world!" cr bye