Soon Tcl became kind of a cult, as programmers around the globe implemented and made available extension libraries for different purposes. Although these libraries are still called extensions because they are not part of the Tcl language itself, many extension packages have become so closely associated with Tcl that they are considered almost a standard Tcl feature.

• tclObjSrv -- for Objectserver
  The tclObjSrv library is a Tcl Motif interface to the IRIX Cadmin distributed object system; see objectserver(1M) for details.
• rstat -- Kernel Statistics
  The rstat library is a Tcl interface to the rstatd kernel statistics daemon; see rstatd(1M) for details. This library is self-initializing: the first time you call an rstat procedure, SGITCL does a dlopen of librstat.so. The rstat library offers two commands that can be used to gather remote statistics from within Tcl programs
• sautil -- for Network Maps
  The sautil library is a Tcl interface to system administration utilities for dealing with network information maps, for example YP maps for password, group, hosts, networks, protocols, and services.
• SNMP -- Simple Network Management
  The snmp library is a Tcl interface for SNMP (simple network management protocol) as implemented on IRIX 6.2. The snmp library is self-initializing: the first time you call one of its library procedures, SGITCL does a dlopen of libsnmp.so.
• wwwHelp -- Web Browser Help
  The wwwHelp library is a Tcl Motif interface to build a help menu that invokes the Netscape Web browser for displaying help. The wwwHelpMenu routine reads a ViewKit helpmap file, by default from /usr/share/help, and constructs a help menu.
• sgiHelp -- ViewKit Help
  The sgiHelp library is a Tcl Motif interface to the entire range of ViewKit help facilities.
• Support for Silicon Graphics Widgets

Tcl is an interpreted language originally intended for use as an embedded command language for other applications. It has been used for that, but has also become useful as a language in its own right.

Tcl Toolkits

Tcl was extended with a set of widgets called Tk. These are not based on the Xt intrinsics, but are built above Xlib. Tk provides an easy way to write X11 applications.

The standard set of widgets in the X world is now the Motif set. Motif offers a large number of widgets, which have seen a lot of development over the last five years. Use of Motif is sometimes a requirement by business, and other widget sets try to conform to Motif in appearance and behavior. Furthermore, many toolkits use Xt-based widgets, so an Xt-compatible interface builder is often useful.

Tm allows the programmer to use Motif widgets instead of Tk widgets from within Tcl programs. This increases programmer choices, and allows comparison of the features of the Tcl Motif and the Tk style of widget programming.

Tm is based on Tk for its style of widget programming, because Tk provides a good model, and to allow Tcl programmers to work with both Tk and Tcl Motif. An alternate style is the WKSH system, a binding of the Korn Shell to the Motif library.

Reading This Chapter

The first two sections, "Getting Started" and "Widget Basics", present basic Motif concepts and are intended for Motif beginners.

The remaining sections, starting with "Resources", constitute a full reference manual for Tcl Motif, with tables of supported resources with their default values, lists of callbacks, and example programs.