Quick summary of the ongoing work.

ROADMAP.md

@@ -3,8 +3,16 @@
 ## Things we are currently doing:
 
 1. [Diff summaries][] for C & JavaScript. Q3 2016 or so.
+
+  - Modelling the abstract semantics of the supported languages. Good summaries require us to know what different parts of the syntax represent.
+  - Performance/responsiveness. We need to be able to produce diffs more quickly, and without unicorns. Some of this will involve front-end work (e.g. requesting summaries out-of-band).
+
 2. [Semantic diffs][] on .com for C & JavaScript. Q4 2016 or so.
 
+  - Performance, as above.
+  - Resilience. A fault in `semantic-git-diff` should not break anything else.
+  - Metrics. We need to know how it’s behaving in the wild to know what to do about it. This also includes operational metrics such as health checks.
+
 ## Follow-up things:
 
 1. Add support for more languages: [Ruby][], etc.
@@ -24,7 +32,7 @@
 
 1. APIs/tooling for data science & engineering teams.
 2. Collect data on our heuristics &c. and refine them via e.g. ML.
-3. Diffs as a service.
+3. Diffs as a [service][].
 
 [Diff summaries]: https://github.com/github/semantic-diff/milestones/Summer%20Eyes
 [Semantic diffs]: https://github.com/github/semantic-diff/milestones/Dot%20Calm
@@ -36,3 +44,4 @@
 [table of contents]: https://github.com/github/semantic-diff/issues/16
 [Jump to symbol definition]: https://github.com/github/semantic-diff/issues/6
 [variables]: https://github.com/github/semantic-diff/issues/91
+[service]: https://github.com/github/platform/blob/master/services/README.md