Thanks to a tip off from Jared 'Ren' Williams, Cairo is the 'next generation' vector graphics library for Linux and is available in PHP as well. The extension was created using PEAR::CodeGen_PECL, writes Harry Fuecks in a new post on his blog.

This raises the question of whether it’s time to depreciate GD? According to Harry the PCRE extension are the two main problem children preventing PHP from being thread safe. It may be possible to replace PCRE and preserve backwards compatibility, with ICU regexes, which claim to be based on Perl’s regular expressions. Dropping GD would be much more painful but with Cairo and the imagick extension, there might be enough to keep everyone happy. This is in the interest of running PHP under Apache 'mpm'.