You've misunderstood. The blog post is not talking about running random binaries. It's talking about opening links and files using different programmes, like PDF viewers, video players, etc. There's a video of a talk that the developer gave, which I can't find the link to at the moment, where he demonstrates running a map programme (already installed on the machine, not just fetched from a random website) to open a link with lat/lon coordinates with an interactive map.
In general, Dillo follows the Unix philosophy. You use separate programmes to handle things that Dillo can't itself, like watching videos.
In general, Dillo follows the Unix philosophy. You use separate programmes to handle things that Dillo can't itself, like watching videos.