For systems administrators, thin-client/server technology is a compelling proposition. In a centrally managed environment, an administrator can provide anything from tightly controlled data-entry applications to full-range desktop productivity software suites on Windows-based terminals (WBTs). Although this solution requires beefy servers, and the thin clients aren't inexpensive, the solution has measurable benefits, such as lower administrative overhead and security advantages.

Thin-client/server solutions made Citrix a name in the industry and motivated Microsoft's development of Windows 2000 Server Terminal Services. Now SCO wants an inroad to this marketplace.

For SCO, the lure of moving its application-hosting product, Tarantella, to the Windows 2000 (Win2K) and Windows NT platforms has proved irresistible. Tarantella displays multiuser NT applications on thin clients. Tarantella runs on a UNIX server or server farm and provides client access to applications that run on a Win2K or NT application server. Future versions of Tarantella will run four versions of Linux, AIX, Tru64, and Sun Solaris.

Tarantella can send the screen display to IBM 3270 green-screen terminals and Wyse Technology's terminals and send X applications to any browser that contains a Java Virtual Machine (JVM). Tarantella uses Adaptive Internet Protocol (AIP), which SCO optimized to send X11 over a dial-up IP connection. In January 2000, SCO released Tarantella Enterprise II, which runs NT applications on UNIX. Tarantella Enterprise II translates RDP from the terminal to AIP, then transmits AIP as a wire protocol to the thin clients to display.

Now SCO has a product that directly competes with Citrix MetaFrame and provides access to applications running a variety of OSs, such as UNIX. Administrators can use Win2K and NT application servers running Terminal Services or NT Server 4.0, Terminal Server Edition (WTS) to support heterogeneous clients. SCO claims that Tarantella offers more centralized management, greater security, better scalability, and a broader support system than MetaFrame.

SCO has set its product prices to aggressively compete with MetaFrame and established a new marketing team for Tarantella. Peter Bondar, SCO vice president of Tarantella marketing, said, "We decided to pick Citrix as our No. 1 competitor to steal business from."

Tarantella Enterprise II will sell for $4925 for a 25-user edition, $100 less than Citrix charges MetaFrame customers for 15 users. SCO also offers aggressive trade-ins for MetaFrame customers wanting to switch to Tarantella. Citrix users can trade 10 MetaFrame licenses for one Tarantella license. In this way, SCO hopes to make inroads into Citrix's $300 million MetaFrame business. Christa Anderson, editor of Windows 2000 Magazine's Thin-Client UPDATE, said, "An estimated 90 percent of enterprise-level WTS deployments use MetaFrame to add value to the terminal server environment."

Tarantella supports a three-tier architecture (vs. MetaFrame's two-tiered one) and lets administrators connect servers into a 50-server load-balanced array that can serve as many as 15,000 users. In Tarantella, the first tier houses the application servers, the second tier houses the Tarantella middleware servers, and the third tier houses the clients. Application servers can run Terminal Services, WTS, IBM 3270, and many types of UNIX (but not Linux). SCO suggests that Tarantella is better suited for data center applications than MetaFrame is because Tarantella will run more types of applications than any other thin-client/server solution and is fully Web-enabled. Tarantella also saves a session's state information (as WTS and MetaFrame do) so that a user can log back on to the system and resume work. Clients in the third tier can connect using RDP, X11, TN3270, Wyse 60, and VT52-420. Tarantella doesn't support ISA.

SCO is also segmenting the thin-client/server market. Tarantella Express is a low-cost version designed for small businesses. SCO packages this product with features such as automated setup and configuration wizards to make deployment easier.

In February 2000, SCO announced an initiative to apply Tarantella to the rapidly developing application service provider (ASP) market. SCO is considering using Tarantella as a hosting business or as an application portal. According to Mike Orr, SCO senior vice president of worldwide marketing, SCO might change its company name or spin off Tarantella as a separate business unit.

Can SCO succeed in the Win2K and NT market? Possibly. Although the economics of Tarantella are attractive, SCO needs to convince companies that it's serious about the NT thin-client/server business and that it has staying power. SCO can attract the interest of Value Added Resellers (VARs), but attracting resellers will take time. The market is in place for SCO to succeed. As an indication of how well Citrix has done, consider that the company signed up 3400 developers (from 70 countries) and 100 independent software vendors (ISVs) to the Citrix Developer Network (CDN) in only 3 months.