Dmytro Shteflyuk

CodeColorer lets you insert syntax-highlighted code snippets into posts, comments, and feeds.
CodeColorer currently bundles GeSHi 1.0.9.0 from the upstream 1.0.x line, with a small set of project-local maintenance patches for current PHP and WordPress compatibility.
Plugin based on GeSHi library, which supports most languages. CodeColorer has various nice features:
<ul>
<li>syntax highlighting in RSS feeds</li>
<li>syntax highlighting of a single line of code (inline)</li>
<li>syntax highlighting of code in comments</li>
<li>line numbers</li>
<li>automatic links to the documentation inserting</li>
<li>code block intelligent scroll detection (short code would have a short block, for a long one the block height would be fixed and a scrollbar would appear)</li>
<li>predefined color themes (Slush & Poppies, Blackboard, Dawn, Mac Classic, Twitlight, Vibrant Ink, Railscasts, Solarized Light, Solarized Dark)</li>
<li>syntax colors customization in CSS file</li>
<li>code protect from mangling by WordPress (for example, quotes, double-dashes, and others would look just right as you entered)</li>
</ul>
<h4>Support</h4>
If you have any suggestions, found a bug, wanted to contribute a translation to your language, or just wanted to say “thank you”, feel free to email me <a href="mailto:kpumuk@kpumuk.info" rel="nofollow ugc">kpumuk@kpumuk.info</a>. I will try my best to answer you.
If you want to contribute your code, see the Development section under the Other Notes tab.
<h3>Supported languages</h3>
Here is the list of languages supported by CodeColorer: 4cs, 6502acme, 6502kickass, 6502tasm, 68000devpac, abap, actionscript, actionscript3, ada, aimms, algol68, apache, applescript, apt_sources, arm, asm, asp, asymptote, autoconf, autohotkey, autoit, avisynth, awk, bascomavr, bash, basic4gl, batch, bf, biblatex, bibtex, blitzbasic, bnf, boo, c, c_loadrunner, c_mac, c_winapi, caddcl, cadlisp, ceylon, cfdg, cfm, chaiscript, chapel, cil, clojure, cmake, cobol, coffeescript, cpp-qt, cpp-winapi, cpp, csharp, css, cuesheet, d, dart, dcl, dcpu16, dcs, delphi, diff, div, dos, dot, e, ecmascript, eiffel, email, epc, erlang, euphoria, ezt, f1, falcon, fo, fortran, freebasic, freeswitch, fsharp, gambas, gdb, genero, genie, gettext, glsl, gml, gnuplot, go, groovy, gwbasic, haskell, haxe, hicest, hq9plus, html4strict, icon, idl, ini, inno, intercal, io, ispfpanel, j, java, java5, javascript, jcl, jquery, julia, kixtart, klonec, klonecpp, kotlin, latex, lb, ldif, lisp, llvm, locobasic, logtalk, lolcode, lotusformulas, lotusscript, lscript, lsl2, lua, m68k, magiksf, make, mapbasic, mathematica, matlab, mercury, metapost, mirc, mk-61, mmix, modula2, modula3, mpasm, mxml, mysql, nagios, netrexx, newlisp, nginx, nimrod, nsis, oberon2, objc, objeck, ocaml-brief, ocaml, octave, oobas, oorexx, oracle11, oracle8, oxygene, oz, parasail, parigp, pascal, pcre, per, perl, perl6, pf, phix, php-brief, php, pic16, pike, pixelbender, pli, plsql, postgresql, postscript, povray, powerbuilder, powershell, proftpd, progress, prolog, properties, providex, purebasic, pycon, pys60, python, q, qbasic, qml, racket, rails, rbs, rebol, reg, rexx, robots, rpmspec, rsplus, ruby, rust, sas, sass, scala, scheme, scilab, scl, sdlbasic, smalltalk, smarty, spark, sparql, sql, standardml, stonescript, swift, systemverilog, tcl, tclegg, teraterm, texgraph, text, thinbasic, tsql, twig, typoscript, unicon, upc, urbi, uscript, vala, vb, vbnet, vbscript, vedit, verilog, vhdl, vim, visualfoxpro, visualprolog, whitespace, whois, winbatch, xbasic, xml, xojo, xorg_conf, xpp, xyscript, yaml, z80, zxbasic.
<h3>Development</h3>
Sources of this plugin are available both in SVN and Git:
<ul>
<li><a href="https://plugins.svn.wordpress.org/codecolorer/" rel="nofollow ugc">WordPress SVN repository</a></li>
<li><a href="https://github.com/kpumuk/codecolorer/" rel="nofollow ugc">GitHub</a></li>
</ul>
The GitHub repository includes local contributor tooling based on <code>mise</code>, Composer, <code>pnpm</code>, and <code>wp-env</code>. A typical setup is:
<ol>
<li><code>mise install</code></li>
<li><code>mise run bootstrap</code></li>
<li><code>mise run test</code></li>
<li><code>mise run wp-start</code></li>
</ol>
Feel free to check them out, make your changes and send me patches or pull requests. Promise, I will apply every patch (of course, if they add a value to the product). Email for patches, suggestions, or bug reports: <a href="mailto:kpumuk@kpumuk.info" rel="nofollow ugc">kpumuk@kpumuk.info</a>.
If you’re interested in translating CodeColorer to your language, please check out the <a href="https://translate.wordpress.org/projects/wp-plugins/codecolorer" rel="nofollow ugc">translation page</a> for the plugin.
<h3>Customization</h3>
Syntax coloring is highly customizable: you could change the color scheme for all languages or a specific language. You could find CodeColorer CSS in wp-content/plugins/codecolorer/codecolorer.css file. To change colors for all languages edit lines below Color scheme section.
There is a simple mapping between TextMate color themes and CodeColorer ones:
<pre><code>/* "Slush & Poppies" color scheme (default) */
.codecolorer-container, .codecolorer { color: #000000; background-color: #F1F1F1; }
/* Comment */
.codecolorer .co0, .codecolorer .co1, .codecolorer .co2, .codecolorer .co3, .codecolorer .co4, .codecolorer .coMULTI { color: #406040; font-style: italic; }
/* Constant */
.codecolorer .nu0, .codecolorer .re3 { color: #0080A0; }
/* String */
.codecolorer .st0, .codecolorer .st_h, .codecolorer .es0, .codecolorer .es1 { color: #C03030; }
/* Entity */
.codecolorer .me1, .codecolorer .me2 { color: #0080FF; }
/* Keyword */
.codecolorer .kw1, .codecolorer .kw2, .codecolorer .sy1 { color: #2060A0; }
/* Storage */
.codecolorer .kw3, .codecolorer .kw4, .codecolorer .kw5, .codecolorer .re2 { color: #008080; }
/* Variable */
.codecolorer .re0, .codecolorer .re1 { color: #A08000; }
/* Global color */
.codecolorer .br0, .codecolorer .sy0 { color: #000000; }
</code></pre>
Check the codecolorer.css file to get more examples.

CodeColorer

Syntax highlighting for code snippets in posts, comments, and RSS, with inline code, themes, and line numbers.

Pedro

LINER In-Site makes your website ‘highlight-able’. 
Visitors will be able to highlight on your website and share highlighted link with others.
Major features in LINER In-Site includes: 
* Highlight your blog or web page. 
* Share highlighted web page to your friends via Facebook, Twitter, and Permalink 
PS: Please subscribe your email on our website(https://connect.getliner.com/api/in-site) and receive further updates and changes.

LINER In-Site

LINER helps you highlight sentences on the web. Highlight your favorite texts.

CodeColorer vs LINER In-Site