  Modern software development requires developers to find and effectively
utilize new APIs and their documentation, but documentation has many well-known
issues. Despite this, developers eventually overcome these issues but have no
way of sharing what they learned. We investigate sharing this
documentation-specific information through \textit{annotations}, which have
advantages over developer forums as the information is contextualized, not
disruptive, and is short, thus easy to author. Developers can also author
annotations to support their own comprehension. In order to support the
documentation usage behaviors we found, we built the Adamite annotation tool,
which supports features such as multi-anchoring, annotation types, and pinning.
In our user study, we found that developers are able to create annotations that
are useful to themselves and are able to utilize annotations created by other
developers when learning a new API, with readers of the annotations completing
67% more of the task, on average, than the baseline.
