





                          Preface

          The X window system is a network-transparent, portable  win-
          dow  system  developed  by Project Athena and the Laboratory
          for Computer Science at the Massachusetts Institute of Tech-
          nology,  with funding and participation by Digital Equipment
          Corporation and International Business Machines, Inc.  X  is
          now  appearing  on computers made by an increasing number of
          companies.  This enables network-transparent X  applications
          to  operate  seamlessly across diverse machine architectures
          and networks.


          The low-level programming interface to the X  window  system
          is contained in the Xlib library, also called the X library.
          Three additional sets of  routines  are  included  with  the
          standard  Xlib  as minimal program development tools: XMenu,
          Xtext, and Xtty.


          However, Xlib by itself is not sufficient for  a  programmer
          to  easily  develop applications that have advanced user in-
          terface features such as pop-up menus or panels  filled  ei-
          ther  with  standard interactive gadgetry (such as push but-
          tons or scroll bars) or with custom gadgetry (such as  ther-
          mometers  or  gauges)  that  the  programmer  might  care to
          develop.


          Although it is generally acknowledged that  the  standard  X
          distribution  needs  a  user interface library that is well-
          matched to X, the definition of a standard X user  interface
          library has only just begun.  The relation between the even-
          tual  standard  and  the toolkits provided in this directory
          (or  any  other  publicly  available user interface library)
          hasn't been determined.  _T_h_e_r_e_f_o_r_e, _i_t _c_a_n'_t  _b_e  _g_u_a_r_a_n_t_e_e_d
          _t_h_a_t _a_n_y _e_a_s_y _p_o_r_t_i_n_g _p_a_t_h _w_i_l_l _e_x_i_s_t _b_e_t_w_e_e_n _t_h_e_s_e _t_o_o_l_k_i_t_s
          _a_n_d _t_h_e _e_v_e_n_t_u_a_l _s_t_a_n_d_a_r_d.  These toolkits are not  provided
          to dictate a _d_e _f_a_c_t_o standard, but rather to prompt discus-
          sion in the X community about what is needed in  a  standard
          and  to  assist  those whose current needs require immediate
          availability of a user interface library, even if it isn't a
          standard.


                      Steven R. Lerman
                      Director, Project Athena
                      Massachusetts Institute of Technology
                      Cambridge, Massachusetts








                     December 23, 1986


