Hi Thanos,
I'm co-author of thinBasic. The other co-author is Roberto Bianchi. Than there are some passionated users that have developed some of the many thinBasic modules.
thinBasic has a modular structure: one main Core module (in charge of parsing, memory/data handling, string and math handling, script flow, ...) plus many other modules loaded at runtime when script request them and in charge of specific keywords: User Interface (GUI: next version will have dialogs and acontrol callbacks), Console programming, advanced math (next version will have matrix calculus), TBGL (OpenGL and games module) ... there are many.
Apart main Core engine module, all modules can be developed by anyone using different languages and thinBAsic SDK. We develop thinBAsic SDK to be used by PowerBasic, FreeBasic, C/C++, Delphi, ASM. Bealive or not thinBasic has also an inline assembler called Oxygen you can find
here and developed with thinBasic SDK for FreeBasic.
The important thing to consider at first is if you need an interpreter or a compiler. thinBasic is 100% a Basic Interpreted Language. Even if thinBasic is able to create executables, they are "bundled" executables that is the original script is bundled with all the needed libraries (plus whatever you need to add inside it) into an executable that will extract needed files every time it is executed. It is a common way to create executable but many so called "compilers" do not say it. So if you need a compiler, go with something like PureBasic, FreeBasic, PowerBasic, ...
Regarding thinBasic syntax you mentioned, yes it is very close to PowerBasic for the only reason we like the coherence of PowerBasic syntax and how it is evolved during those many years. Coherence is one of the aspects we consider important in language development.
If you are a searching execution speed, do your tests by yourself. thinBasic speed is quite remarcable comparing with other interpreted language. Because you are familiar with AutoIt, make some comparing tests and you will notice ... something. I'm very fond of AutoIt too especially for UI area but when dealing with math calculations and speed in general thinBasic is another thing.
That said, if you think thinBasic con do some of the job you need, please register to thinBasic forum and feel free tro ask whatever you will need. I'm sure you will get you reply very soon. Despite thinBasic is free, we also try to maintain a professional help material. A 1.6MB .CHM file is included in thinBasic distribution. Plus, the same file and a HTML version can be downloaded at
http://www.thinbasic.com/index.php?opti ... &Itemid=66 or viewed online at
http://www.thinbasic.com/public/product ... index.html
In help material you will find thinBasic keywords divided by modules. Every keywords (apart the ones in Core module) are available only if the script ask to load a specific module.
Also consider we are very fast in development phase so if something is missing and you ask for it, do not be surprised to have it done the next few days.
Ciao
Eros