Currently, Comments doesn't implement a history interface (this is a ticket separate of T146589. Once the actual editing feature is implemented, then this should be worked on). Some pointers:

• This could be easily implemented if each Comments is considered it's own page in a collective namespace in say, the Comments namespace. This is currently how Wikia's Comments do this, and calls the namespace "User blog comments". There are two major downsides to this however:
  • This creates tons of unnecessary pages (at least in my opinion?) and can be considered to clutter the wiki.
  • This will leave the wiki-version of technical debt on a wiki if say, Comments is uninstalled. If Comments is a popular used extension and that wiki decides to uninstall it, then it just leaves hundreds of pages that need to be deleted. This is a hypothetical situation but I believe it's realistic and can happen. (this happened on the LEGO Batman ShoutWiki, actually, where there were tons of threads and comments that needed to be deleted).
• We use Special:Log/comments and pull out relevant log entries for each specific comment to create a history, which could possibly be viewed by opening a dialog that could be clicked from opening a dropdown menu in the comments interface (will need not only code review but also design critique (although I'm fine with that) ) This would most likely be quite a performance hit.
• Create our own history (somehow? I don't like this idea, there's already things that provide histories and we don't need to reinvent the wheel. Creating our own history would mean creating our own technical debt, which would be code duplication. It's an option, but unrealistic nevertheless IMO)

Thoughts @ashley?