Commercial Software

ProvideX [Code]

Multiplatform programming environment for Windows, OS X, Linux, FreeBSD and others.
Designed for business use.

QBasic / QuickBASIC [Code]

Classic BASIC compiler and interpreter on DOS.

REALbasic [Code]

Multiplatform Visual Basic style programming environment for Windows, OS X and Linux.
Designed for business use.

Visual Basic [Code]

Visual Basic 6 and earlier, VBA and VBScript on Windows.
General purpose, office development & scripting.

Visual Basic .NET [Code]

OOP development on Windows: commercial Standard and Professional editions.

FreeWare Software

AutoIT [Code]

BASIC-like automation & scripting language for any version of Windows.

thinBasic [Code]

Free modular scripting tool for Windows.
Open Source Software

BaCon [Code]

BaCon is a simple Basic implementation which translates into C-code.

BCX [Code]

BCX is a small command line tool that inputs a BCX BASIC source code file and outputs a C source code file which can be compiled with many C or C++ compilers.

CellularBASIC [Code]

BASIC interpreter for Java enabled handhelds, smartphones, mobilephones, cellular phones and PDAs.
Dialect of QBasic 1.1 syntax.

FreeBASIC [Code]

Multiplatform BASIC compiler for Windows, DOS and Linux.
Designed for general purpose & QBasic compliance.

Gambas [Code]

Visual Basic style programming environment for Linux.

ScriptBasic [Code]

BASIC interpreter for Windows, OS X, Linux and web environments.