I have released version 1.3.0 of WP-GeSHi-Highlight. WP-GeSHi-Highlight is a popular code syntax highlighting plugin for WordPress, based on the established PHP highlighting library GeSHi.

These are the changes compared to version 1.2.3:

• Enhance compatibility of the default stylesheet with a large range of themes by increasing the specificity of certain CSS selectors and by adding more style directives. This ensures a better out-of-the-box experience. Thanks to Pascal Krause for reporting an incompatilibity with Twenty Ten.
• Increase compatibility with CDNs: fix double slash appearing in CSS file URL.
• Remove redundant call to wp_register_style().
• Change style sheet ID prefix, add newline characters to GeSHi CSS code output.
• Improve code documentation and readability.

In fact, this update contains a considerably consolidated default stylesheet (with just a minimal set of changes). I have verified that it works well with all recent versions of the important official themes:

• Twenty Ten (version 1.9)
• Twenty Eleven (version 2.1)
• Twenty Twelve (version 1.7)
• Twenty Thirteen (version 1.5)
• Twenty Fourteen (version 1.4)
• Twenty Fifteen (version 1.2)

I have also tested the new default style sheet with the following popular themes: Vantage, Customizr, ColorWay, Zerif Lite, Responsive, Storefront, Virtue, evolve, Make, Sparkling, Spacious, Enigma, Sydney, Point, Interface, SinglePage.

I want to use this opportunity to stress how much I like the recent community developments around WP-GeSHi-Highlight. Almost five years have passed since I first released this plugin to the WP repository, and I never really put effort into spreading it. Nevertheless, according to the WordPress statistics, it is used on more than one thousand websites. I have searched the web to find a few examples about who uses this plugin for which purpose, and want to share two of my findings:

• In this StackOverflow thread, Aaron Bertrand, a ninja database expert, revealed that he likes the GeSHi-based approach so much (and he uses WP-GeSHi-Highlight in his blogs), that he was willing to provide a huge bounty to someone helping him out to improve the syntax highlighting for the T-SQL language in subtle ways. Another ninja joined the discussion for helping Aaron, and Aaron had more wishes like “There’s always one little extra thing, right? I promise this is it. I want to color the N prefix on Unicode strings in red.”. They found their solution, great. I proposed to them to contribute their findings upstream, straight to GeSHi, so that I, further downstream, can incorporate them in WP-GeSHi-Highlight at some point. I love this.

• On Make Create Reiterate, Tina Dvyver uses WP-GeSHi-Highlight (and writes about it) as of its support for an exotic language in the world of highlighters, X++. What I like about her blog is that she actually took her time to adjust the default stylesheet to her needs, and that she came up with a neat way to hide the dots in the numbered list, when using line numbering. She writes about it here.

One more thing I want to mention: in the past days I had a productive discussion with two users of this plugin, in this support thread. Turns out that WP-GeSHi-Highlight was not responsible for the issue reported there, but this discussion still lead to fixing the double-slash issue mentioned above in the change log. It also lead to me knowing of one more person who actively transitioned from WP-Syntax to WP-GeSHi-Highlight, and to one more review on the wordpress.org plugin page.

I realize that I should put more effort into spreading this plugin, as it has obvious architectural advantages over heavy client-side highlighters. Unfortunately, most of the “Top X syntax highlighting plugins for WordPress” blog posts around the web do not really clarify the significant difference between back-end highlighters and client-side ones. I’ll possibly cover that in a future blog post.