1. Introduction

ScriptBasic is a scripting implementation of the programming language BASIC. The interpreter has several features that make it a considerable choice when program designers want to choose an interpreter to embed into an application.

The aim of the implementation of this interpreter was to deliver a programming language that can be powerfully used to program several tasks by programmers without learning a new system, a new programming language. Thus the language BASIC was chosen and was implemented in a interpreter with the following features:

• IT IS BASIC. No question, this is the MOST important feature of ScriptBasic. There are a lot of people who can program BASIC and only BASIC. There are many people, who can not really program. Those who do not really know what programming is, and still: they write their five-liners in BASIC to solve their simple problems. They never write Perl, Tcl, Java or C. Therefore it is BASIC.

• SCRIPTING language. There are no data types in the language. You can store real numbers, integer numbers and strings in any variable. You can mix them and conversion is done automatically.

• PORTABLE Available in C source and can be compiled on UNIXes as well as on Windows NT.

• 4E LANGUAGE, which means easy to extend, easy to embed. ScriptBasic was developed to provide clean and clear interfaces around it, and inside it. It is

  easy to embed the language to an application and use it as a macro language just like TCL. It is also easy to implement new built-in function and new commands. You can develop dynamically loaded libraries that ScriptBasic may load at run time. The language source is clean, well documented and development guides are on the way.

• COMPILED CODE ScriptBasic creates intermediate compiled code, which is interpreted afterwards. Syntax analysis is done at first and only syntactically perfect programs start to run. The compiled code is put into a continuous memory space and compiled code can be saved and loaded again to run without recompilation. This is vital for CGI scripts and is not available for most scripting programming languages. Compiled code is binary, not readable. Therefore you can develop and distribute programs and getting some help to protect your intellectual property. You need not give the source code.

• MULTI THREAD aware. Although the current implementation is not multi thread, all the code was designed to be thread safe. You can embed the code into systems that run multiple interpreters in the same process. On the other hand the interpreter can run the same code in multiple threads and was designed to be capable handling call-back functions, and multithread programs in the future.

• DEBUGGER The BASIC programs can be debugged using the external debugger.