Some might regard the Vita as a "mobile dust collector model of the Wii U" but that doesn't make it any less of a gaming platform.
To that end, a redditor has discovered that there are a number of booths at E3 related to "3D Development" on the PS Vita—notably Rebellion, the makers of the Sniper series of games; and Virtuos Games, which did the PSP version of Ghost Recon, among many other games. The latter studio is also known for their console versions of the Civilization games. Beyond 3D Development, Rebellion also has slots under Arcade and Adventure.
Other companies also involved in developing PS Vita games include Aksys Games, which is listed under localization as well as action. The studio has previously stated that it intends to announce two new games. Atlus, Rebellion, and XSEED are also listed under the PlayStation Vita's Action section.
Here's everything else, as discovered by the redditor.
Vita Audio and Sound – ASTRO Gaming / Skullcandy – I guess some headsets
Vita Audio and Sound – Monoprice
InComm is listed under several, such as casual gaming. They do virtual currency.
Vita Localization – Pole to Win
Vita Localisation – Digital HEARTS
Vita Distribution – Bigben Interactive, or listed under racing.
Vita Distribution – BBR-1 America
Vita Distribution – KEMCO
Vita Distribution – Mecca Electronics
Vita Strategy – BradyGames – They make strategy guides, so I guess they have some for Vita, or a strategy App.
Vita RPG – Tecmo Koei America Corporation – Probably Atelier Meruru
Vita RPG – Deep Silver, Inc. – Did Mytran Wars for PSP and Sacred Citadel recently Vita RPG – aksys
Vita RPG – xSEED
