Independent developer Hothead Games and gaming webcomic Penny Arcade today announced Greenhouse, a website that will focus on selling downloadable independent games for PC, Mac and Linux.

Hothead and Penny Arcade's RPG Penny Arcade Adventures: On the Rain-Slick Precipice of Darkness, Episode One will be the first title to release on the platform. No date has been announced for the title's debut, though it will sell for $19.95 and is expected this spring.

According to the company, Greenhouse was "built to supplement other online game delivery platforms," such as Valve's Steam, which provides Penny Arcade comics to its users.

"There are so many great games out there that you don't hear about," explained Penny Arcade business director Robert Khoo. "They're too niche or too risky in terms of game play for the top publishers to be comfortable with distributing. We want the Greenhouse to be an alternative for these developers."

A beta of Greenhouse and its downloading application are currently available at www.playgreenhouse.com.

An NPD analyst says that the $60 million drop in PC software retail revenue from 2006 to 2007 reflects the industry's movement towards digital distribution, GameDaily reports.

Analyst Anita Fraisure notes that the data, which currently does not account for digital downloads or subscriptions, is no cause for concern.

"As we've seen from a number of our studies, the PC continues to be a top platform in terms of total game playing time," said Fraisure. "I don't think this slight decline in retail sales is anything more than a reflection of a shifting of distribution channels."

The latest numbers reveal that PC sales accounted for only 14% of total revenue for game software sales in 2007. But without a comprehensive perspective of online activity, Fraisure says, the implications of the gap remain unclear.

"Video games software sales, and even just the console portion of that figure have been greater than PC retail sales every year that we've tracked. Yes, the (console and portable) video games retail sales have really exploded, but again, until we can get a measurement of dollars spent online, we won't have the true picture."

Steel Penny Games today revealed itself to the general public, announcing its intent to focus on digitally distributed titles. The developer represents the latest studio centered around digital distribution, a category that includes Blazing Lizard, the Kuju-owned doublesix, Wideload Shorts, and many others.

The first release out of Steel Penny, which was formed early last year by ex-Naughty Dog tools engineer Jason Hughes and background artist Andrew Gilmour, is a puzzle game starring the cat-dog duo Bruiser and Scratch (pictured above). It is slated to arrive on WiiWare in mid-2008.

Said to launch in early 2008, WiiWare marks Nintendo's latest addition to the online Wii Shop Channel. Unlike the Virtual Console portion, which sells straight ports of old games, WiiWare will focus on original titles.

Thus far, Virtual Console sales have brought in almost $32 million, and many are hoping for a repeat of that success with WiiWare. Advocates of digital distribution argue that such a model--recently introduced in the realm of consoles via Xbox Live Arcade, WiiWare, and PlayStation Network--allows for more creativity, lower project costs, shorter development time and higher returns.

Exent Technologies has announced today that they are partnering with Microsoft to bring many of Microsoft Game Studios' PC games to the digital distribution arena. Exent, whose technology powers Yahoo! Games' games-on-demand service, already has a similar partnership with publisher Atari. However, the press release did not specify if Microsoft's games would be made available through a Microsoft-only service (like Atari on Demand), or whether they would be integrated into larger services such as Comcast on Demand.

"Microsoft is committed to helping expand the PC game industry. By making our titles available through Games-on-Demand services, we can broaden our reach to new audiences and monetize additional release windows." said Ed Ventura, Director of Franchise Development, Xbox Worldwide Content and Marketing at Microsoft. Exent's distribution channels help us to extend the lifecycle of our game catalog and to build a firm foundation for the future.

With Exent's technology, Valve's Steam service, Nintendo's upcoming vintage game download service for Revolution, Microsoft's Xbox Live Arcade, and the eventual release of the Phantom console, digital distribution is starting to heat up.