Editing FreeBASIC (section)

==Compiler features==
On its [[Front and back ends|backend]], FreeBASIC makes use of [[GNU Binutils]] in order to produce console and [[graphical user interface]] applications.  FreeBASIC supports the linking and creation of [[C (programming language)|C]] static and dynamic [[library (computing)|libraries]] and has limited support for [[C++]] libraries.  As a result, code compiled in FreeBASIC can be reused in most native development environments.

While not an [[optimizing compiler]], FreeBASIC can optionally [[Source-to-source compiler|transcompile]] to C to compile with optimizations. FreeBASIC supports [[Inline assembler|inline assembly]], [[Multithreading (software)|multi-threading]], and does not use [[automatic garbage collection]].

[[C preprocessor|C style preprocessing]], including multiline [[macro (computer science)#Text-substitution macros|macros]], conditional compiling and file inclusion, is supported.  The preprocessor also has access to symbol information and compiler settings, such as the [[Dialect (computing)|language dialect]].

===Syntax===
Initially, FreeBASIC emulated Microsoft QuickBASIC syntax as closely as possible. Beyond that, the language has continued its evolution. As a result, FreeBASIC combines several language dialects for maximum level of compatibility with QuickBASIC and full access to modern features.<ref>{{cite web|title=freeBASIC dialects|url=http://www.execulink.com/~coder/freebasic/compare.html|work=coderJeff's home page|access-date=5 February 2012}}</ref>  New features include support for concepts such as [[object (computer science)|object]]s, [[operator overloading]], [[function overloading]], [[namespace]]s and others.<ref>{{cite web|title=Differences from QB|url=http://www.freebasic.net/wiki/wikka.php?wakka=LangQB|work=freeBASIC.net documentation|access-date=5 February 2012}}</ref>

[[Newline]] characters indicate the termination of programming statements. A programming statement can be distributed on multiple consecutive lines by using the underscore ''line continuation char'' (_), whereas multiple statements may be written on a single line by separating each statement with a [[colon (punctuation)|colon]] (:).

Block [[comment (computer programming)|comments]], as well as end-of-line remarks are supported.  Full line comments are made with an [[apostrophe]] <code>'</code>, while blocks of commented code begin with <code>/'</code> and end with <code>'/</code>.

FreeBASIC is not case-sensitive.

===Graphics library===
FreeBASIC provides built-in, QuickBASIC compatible graphics support through FBgfx, which is automatically included into programs that make a call to the <code>SCREEN</code> command.  Its backend defaults to [[OpenGL]] on [[Linux]] and [[DirectX]] on [[Microsoft Windows]].  This abstraction makes FBgfx graphics code cross-platform compatible.  However, FBgfx is not hardware accelerated.

Users familiar with external graphics utilities such as OpenGL or the Windows API can use them without interfering with the built-in graphics library.

===Language dialects===
As FreeBASIC has evolved, changes have been made that required breaking older-styled syntax.  In order to continue supporting programs written using the older syntax, FreeBASIC now supports the following dialects:
* The default dialect (''-lang fb'' as a [[Command-line interface#Arguments|command-line argument]]) supports all new compiler features and disallows archaic syntax.
* The FB-lite dialect (''-lang fblite'') permits use of most new, non-object-oriented features in addition to older-style programming.  Implicit variables, suffixes, <code>[[GOSUB]]</code> / <code>RETURN</code>, [[line number|numeric labels]] and other features are allowed in this dialect.
* The QB dialect (''-lang qb'') attempts to replicate QuickBASIC behavior and is able to compile many QuickBASIC programs without modification.