Editing Duke Nukem 3D (section)

== Source ports ==
{{Anchor|Source code}}
Following the release of the ''Doom'' [[source code]] in 1997, players wanted a similar source code release from 3D Realms. The last major game to make use of the ''Duke Nukem 3D'' source code was TNT Team's ''[[World War II GI]]'' in 1999. Its programmer, Matthew Saettler, obtained permission from 3D Realms to expand the gameplay enhancements done on ''WWII GI'' to ''Duke Nukem 3D''.

''EDuke'' was a semi-official branch of ''Duke Nukem 3D'' that was released as a patch as ''Duke Nukem 3D'' v2.0 for ''Atomic Edition'' users on July 28, 2000. It included a demo mod made by several beta testers.<ref name="EDuke"/><ref name="EDuke-Patch"/> It focused primarily on enhancing the CON scripting language in ways which allowed those modifying the game to do much more with the system than originally possible. Though a further version was planned, it never made it out of beta. It was eventually cancelled due to programmer time constraints. About a month after the release of the ''Duke Nukem 3D'' source code, ''[[Blood (video game)|Blood]]'' project manager Matt Saettler released the source code for both ''EDuke'' v2.0 and EDuke v2.1, the test version of which would have eventually become the next ''EDuke'' release, under the GPL.{{Citation needed|date=January 2015}}

The [[source code]] to the ''Duke Nukem 3D'' v1.5 executable, which uses the Build engine, was released as [[free software]] under the [[GNU General Public License|GPL-2.0-or-later]] license on April 1, 2003.<ref name="SourceCode"/> The game content remains under a proprietary license. The game was quickly ported by enthusiasts to modern operating systems.

The first ''Duke Nukem 3D'' port was from icculus.org. It is a cross-platform project that allows the game to be played on [[AmigaOS]], [[AmigaOS 4]], [[AROS]], [[BeOS]], [[FreeBSD]], [[Linux]], [[Mac OS X]], [[MorphOS]], [[Solaris (operating system)|Solaris]], and [[Windows]] rather than MS-DOS. The icculus.org codebase would later be used as the base for several other ports, including ''Duke3d_32''.<ref name="DN3D-32"/>

Another popular early project is Jonathon Fowler's ''JFDuke3D'', which, in December 2003, received backing from the original author of Build, programmer [[Ken Silverman]].<ref name="jfduke3d"/> Fowler, in cooperation with Silverman, released a new version of ''JFDuke3D'' using [[Build engine#Polymost|Polymost]], an [[OpenGL]]-enhanced renderer for Build which allows hardware acceleration and 3D model support along with 32-bit color high resolution textures. Another project based on ''JFDuke3D'' called ''xDuke'', unrelated to the ''xDuke'' project based on ''Duke3d_w32'', runs on the [[Xbox (console)|Xbox]]. Silverman has since helped Fowler with a large portion of other engine work, including updating the network code, and helping to maintain various other aspects of the engine.{{Citation needed|date=January 2015}} Development was semi-active between 2005 and 2020, since then, new versions are regularly published.

While a few short-lived [[DOS]]-based ''EDuke'' projects emerged, it was not until the release of ''EDuke32'', an extended version of ''Duke3D'' incorporating variants of both Fowler's [[Microsoft Windows]] ''JFDuke3D'' code, and Saettler's ''EDuke code'', by one of 3D Realms' forum moderators in late 2004, that ''EDuke's'' scripting extensions received community focus.<ref name="eduke32"/> Among the various enhancements, support for advanced [[shader model]] 3.0 based graphics was added to ''EDuke32'' during late 2008-early 2009. In June 2008, thanks to significant porting contributions from the [[DOSBox]] team, ''EDuke32'' became the only ''Duke Nukem 3D'' source port to compile and run natively on [[64-bit]] Linux systems without the use of a 32-bit compatibility environment.

On April 1, 2009, an [[OpenGL]] Shader Model 3.0 renderer was revealed to have been developed for ''EDuke32'', named ''Polymer'' to distinguish from Ken Silverman's ''Polymost''.{{Citation needed|date=January 2015}} It allows for much more modern effects such as dynamic lighting and [[normal mapping]]. Although Polymer is fully functional, it is technically incomplete and unoptimized, and is still in development. As of the fifth installment of the ''High Resolution Pack'', released in 2011, the Polymer renderer is mandatory. In 2011, another significant development of ''EDuke32'' was the introduction of true room over room (TROR), where sectors can be placed over other sectors, and can be seen at the same time. In practice, this allows for true three-dimensional level design that was previously impossible, although the base engine is still 2D.

On December 18, 2012, the ''Chocolate Duke Nukem 3D''<ref name="ChocolateDuke3D"/> source port was released. Inspired by ''[[Chocolate Doom]]'',<ref name="chocolateDoom"/> the primary goal was to refactor the code so developers could easily read and learn from it, as well as make it portable.

In February 2013, a source [[code review]] article was published that described the internal working of the code.<ref name="CodeReview"/>