With the launch of the S3 Graphics 5400E, which mentions Linux support in the press release, we headed on over to the S3 Graphics driver area. It turns out that S3 Graphics has a new Linux driver out, which is actually dated for tomorrow and is marked v14.02.26.
This new S3 Graphics Linux driver has numerous bug-fixes, x86_64 Linux support, "API support", support for Ubuntu 9.04 and 9.10, and now it supports OpenGL 3.1 too. Though the release notes mention support for just the Chrome 540 GTX and 530 GT, but not the new 5400E. Beyond OpenGL 3.1 support, this S3 Graphics driver now also has apparently kernel mode-setting and VDPAU support too, in a binary driver update that silently met the Internet this summer.
The S3 Graphics driver for the Chrome 500 series on Linux is available from this page.