It’s taken a long time to get there, but Google are now indexing the content of SVG files.
SVG is a vector graphics format which is similar in structure to the code that makes up an HTML web page. As well as the obvious graphical elements, SVG files often also include text (such as the speech and captions in our comics) and metadata (embedded information about the image – such as the artist’s name, or the license the image is released under). These bits of text should now get indexed by Google.
All our comics start as SVG files created using the free Inkscape application. As we’ve been assiduously inserting metadata into our files right from the start, this should hopefully make it a little easier to find our comics with a Google search.
Our comics are released under a 
... which requires suitable attribution if you use them...
... and doesn't allow commercial use...
... and requires any derivative works to be released under the same licence.
This symbol indicates an SVG file that you can download and use under this licence