  Software language design and implementation often involve specifications
written in various esoteric meta-languages. Language workbenches generally
include support for precise name-based navigation when browsing language
specifications locally, but such support is lacking when browsing the same
specifications online in code repositories.
  This paper presents a technique to support precise name-based navigation of
language specifications in online repositories using ordinary web browsers. The
idea is to generate hyperlinked twins: websites where verbatim copies of
specification text are enhanced with hyperlinks between name references and
declarations. By generating hyperlinks directly from the name binding analysis
used internally in a language workbench, online navigation in hyperlinked twins
is automatically consistent with local navigation.
  The presented technique has been implemented for the Spoofax language
workbench, and used to generate hyperlinked twin websites from various language
specifications in Spoofax meta-languages. However, the applicability of the
technique is not limited to Spoofax, and developers of other language
workbenches could presumably implement similar tooling, to make their language
specifications more accessible to those who do not have the workbench
installed.
