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Note:These pages make extensive use of the latest XHTML and CSS Standards. They ought to look great in any standards-compliant modern browser. Unfortunately, they will probably look horrible in older browsers, like Netscape 4.x and IE 4.x. Moreover, many posts use MathML, which is, currently only supported in Mozilla. My best suggestion (and you will thank me when surfing an ever-increasing number of sites on the web which have been crafted to use the new standards) is to upgrade to the latest version of your browser. If that's not possible, consider moving to the Standards-compliant and open-source Mozilla browser.

February 28, 2019

Instiki 0.30.0 and tex2svg 1.0

Instiki is my wiki-cum-collaboration platform. It has a built-in WYSIWYG vector-graphics drawing program, which is great for making figures. Unfortunately:

  • An extra step is required, in order to convert the resulting SVG into PDF for inclusion in the LaTeX paper. And what you end up with is a directory full of little PDF files (one for each figure), which need to be managed.
  • Many of my colleagues would rather use Tikz, which has become the de-facto standard for including figures in LaTeX.

Obviously, I needed to include Tikz support in Instiki. But, up until now, I didn’t really see a good way to do that, given that I wanted something that is

  1. Portable
  2. Secure
Posted by distler at 2:21 PM | Permalink | Followups (2)

February 15, 2019

Brotli

I finally got around to enabling Brotli compression on Golem. Reading the manual, I came across the BrotliAlterETag directive:

Description: How the outgoing ETag header should be modified during compression
Syntax: BrotliAlterETag AddSuffix|NoChange|Remove

with the description:

AddSuffix
Append the compression method onto the end of the ETag, causing compressed and uncompressed representations to have unique ETags. In another dynamic compression module, mod_deflate, this has been the default since 2.4.0. This setting prevents serving “HTTP Not Modified (304)” responses to conditional requests for compressed content.
NoChange
Don’t change the ETag on a compressed response. In another dynamic compression module, mod_deflate, this has been the default prior to 2.4.0. This setting does not satisfy the HTTP/1.1 property that all representations of the same resource have unique ETags.
Remove
Remove the ETag header from compressed responses. This prevents some conditional requests from being possible, but avoids the shortcomings of the preceding options.

Sure enough, it turns out that ETags+compression have been completely broken in Apache 2.4.x. Two methods for saving bandwidth, and delivering pages faster, cancel each other out and chew up more bandwidth than if one or the other were disabled.

Posted by distler at 9:47 AM | Permalink | Post a Comment