Is there anything particular that did catch your attention? Anyway - it's just standard Vim. I deliberately turned off all scripts for this recording so that watching isn't too confusing. Auto run of tests is handled by guard with Prove extension. It waits for file modification(save) and runs prove for that file and displays result as desktop notification. I'm using black background for them so they don't disturb me much, but they are not part of the Vim.