This is a library that intends to make it easier to write Coq proofs that more closely match paper proofs. This means that there should be automation, as manual proof scripts are impenetrable and fragile, but that hints should be localized to individual proofs. It's quite new! Current features are the following tactics:
hint lemma, lemma, ...
Adds given lemmas/theorems to hints for the current proof goal, to be used by proof search.
hint_rewrite lemma, ...
Similarly, but the end is expected to be an equality, and it will be used for left-to-right rewriting.
hint_rewrite <- lemma, ...
Like hint_rewrite, but for right-to-left rewriting.
hint_simpl
Ask proof automation to try running simpl (not sure how well this works yet).
hint_congruence
Ask proof automation to try running congruence (not sure how well this works yet).
hint_reflexivity
Ask proof automation to try running reflexivity (not sure how well this works yet).
iauto/iauto'
These are just wrappers for try solve [intuition (eauto 3)] and try solve [intuition eauto].
invert
Slightly better inversion -- clears the hypothesis and substs.
simplify
Does some basic predicate logic stuff, removing obvious things, splitting obvious things, etc.