Monday, October 22, 2007, 06:00 am PT (09:00 am ET)
Road to Mac OS X Leopard Server: Collaborative Info Sharing Services
The Unix Wars
In 1988, AT&T aligned with Sun and SCO to create a unified Unix release that paired AT&T's commercial Unix, SunOS, BSD, and SCO's PC compatibility features into the "SVR4" specification. Fearful that Sun already had too much clout in the Unix market, rival Unix vendors led by Digital, IBM, and HP formed their own alliance called the OSF. That division fractured the Unix market and chilled growth and community innovation until the mid 90s, when Unix vendors began working together under the Open Group, as described in SCO, Linux, and Microsoft in the History of OS: 1990s.
In the early 90s, BSDi, a private company founded by developers from UC Berkeley, made efforts to replace AT&T's proprietary software from Unix and distribute substitute code along with the liberally licensed BSD software. AT&T's Bell Labs filed a lawsuit in 1992 that sought an injunction to stop BSD. The case set back the community development of BSD, creating a vacuum that was filled by Linux and the GNU project, resulting in a three way split between the two open, Unix-like operating systems and AT&T's commercial Unix.
Microsoft directly benefited from the technical and political divisions among Unix vendors in the 90s. Windows NT ate into Unix workstation and server sales using the cheaper hardware available in the PC market. That market was also increasingly being targeted by Linux. In 1993, Novel bought the rights to AT&T's Unix in an effort by CEO Ray Noorda to mount an offensive against Microsoft. In 1994 Noorda was pushed out of Novell and he began putting together a similar, independent effort using Linux and involving SCO.
Noorda planned to line up SCO's installed base of users running the ancient Xenix on PC servers, and migrate them to Linux. After retiring from SCO, the company dropped its Linux focus and instead attacked Linux users in an effort to claim copyright infringement on the AT&T Unix code it had acquired from Novell. That case was only recently settled when the courts determined the Novell held all copyrights for Unix, and that SCO had no infringement case, as noted in SCO, Linux, and Microsoft in the History of OS: 2000s.
A Unix Peace
In 1996, Apple began shopping for a new operating system to replace its classic Mac OS. It reviewed Microsoft's Windows NT and dismissed it on its technical merits. It then began talks with Be over acquiring its BeOS, but the operating system was only in early beta developer release and had no application base, in part because it wasn't built on an open Unix foundation. It then stumbled upon NeXT, and in the final days of 1996, Apple acquired the company for its Unix based operating system.
Apple found that NeXT not only offered a bullet proof, Unix-based operating system foundation that had proven itself in sales to financial markets and security agencies such as the CIA and NSA, but also offered advanced development frameworks and was highly portable. NeXT had sold its operating system and operating environment on a variety of hardware platforms, from its own Mac-like NeXT computers to workstations from HP and Sun and even industry standard PCs. NeXT had also already started work in porting its OS to the PowerPC architecture Apple was using.
Up to that point, Apple had been selling a dedicated Mac server application called AppleShare (below), which served up file and print sharing over the AppleTalk protocol to Mac and PC users. It also sold A/UX Unix servers from 1988 through 1994 prior to moving to PowerPC; in 1996 it began selling a line of PowerPC servers called Apple Network Server running IBM's AIX, also based on AT&T's Unix. Between 1993-1998, Apple sold specialized Mac models called the Apple Workgroup Server, either running A/UX or AppleShare on the classic Mac OS. After acquiring NeXT, it now had a modern Unix-based server of its own to sell on PowerPC Macs.
Prelude to Mac OS X Server
Apple had earlier partnered with IBM in the development of Taligent, and had worked with the OSF to host an open source project called mkLinux, designed to woo Linux users to use Mac hardware.
The Taligent and mkLinux projects were based on versions of the Mach kernel, as was NeXTSTEP. Apple paired its own internal developments with NeXT's to develop a new kernel, and incorporated new technology developed by three outside communities of BSD developers: OpenBSD, FreeBSD, and NetBSD.
As Apple discovered how much work was needed to migrate and update all of that code together, it decided to go one step further and remove all proprietary entanglements in the core OS of NeXTSTEP, so it could release the kernel and core OS as open source. While that work was underway, it continued to sell the classic Mac OS-based AppleShare IP (below), which provided file and print sharing, email, and web hosting services on the classic Mac OS.
Apple also sold an essentially rebranded version of NeXTSTEP, code-named Rhapsody, for PowerPC Macs under the name Mac OS X Server 1.0 (below). It supplied similar file sharing and web hosting services, but on top of its new Unix foundation.
Mac OS X Server Releases
Once Apple had completely removed entanglements to commercial Unix using BSD, it released its operating system foundation as the Darwin open source project in April 2000. Among the significant changes was an entirely new Quartz graphics rendering and compositing engine. Server versions of Mac OS X 10.0 and 10.1 mainly carried forward the features of Apple's earlier AppleShare IP product as an upgrade path for its existing server users, mainly in education.
Mac OS X Server 10.2 Jaguar, released in 2002, was the first version of Mac OS X ready for mainstream desktop users. For Jaguar Server 10.2, Apple introduced:
- jHFS+, a journaling version of the Mac file system
- Open Directory, an LDAP based directory server—resurrecting the Open Directory name from PowerTalk era
- an improved QuickTime Streaming Server 4 and QuickTime Broadcaster
- a standardized printing architecture build upon the Common Unix Printing System
- the Xserve, its first custom designed server hardware since the AIX-based Apple Network Servers
- Server Status remote management tools based on SNMP
Those features demonstrated how Apple significantly benefitted from using open source and open standards. It also shared improvements to QuickTime Streaming Server, its file system technology, and other contributions back to the open source community.
Mac OS X Panther Server 10.3, released in 2003, continued to update and incorporate more open source projects into the system. Using Samba 3, Panther Server could act as a Windows domain controller for managing file sharing and directory services to Windows clients. Apple also bundled MySQL and PHP for web development and improved and updated other services, including its mail server.
Mac OS X Tiger Server 10.4, released in 2005, introduced a mix of open source software with an Apple designed user interface, marketed at "Open Source made easy." Rather than configuring the bundled Apache web server, Samba Windows file sharing, and Postfix and Cyrus mail servers by editing text configuration files or from a web interface as is common on Linux servers, Mac OS X Server provides a series of graphical applications for managing services in Server Admin (below), users and groups with Workgroup Manager, and server hardware from Server Monitor.
Apple also added internal support for Access Control Lists. Support for ACLs offers a mechanism for more complex file permissions, compatible with those used by Windows. Tiger also introduced Portable Home Directories, which allow desktop clients to log into a server, download a user profile, and then keep their user directory in sync with the server. This is similar to roaming profiles and synced shared folders in Windows.
Other custom developed additions included Xgrid distributed processing and 64-bit application support. Apple also incorporated its WebObjects deployment server into Tiger Server, which had earlier required a $50,000 license.
Apple also developed an iChat instant messaging server based upon the open Jabber project. This change also appeared in the iChat client: in addition to working with the proprietary AOL IM system, iChat could now be used with any Jabber system, including Google Talk, as noted in Road to Mac OS X Leopard: iChat 4.0.
Tiger Server also bundled Blojsom, a Java version of the Blossom weblog server. Apple designed custom skins for the weblog server, making it easy for companies running Mac OS X Server to set up simple blogs, but it left blogging as a poorly positioned service, since it was painstakingly difficult to make any significant changes to hosted blogs.
On page 3 of 3: What's New in Leopard Server; Leopard's Client-Server Integration; Wiki Collaborative Publishing Services; and Leopard Server vs Microsoft Windows Server.