There is no general framework such as the TransSkel program for the Macintosh
which handles lots of the odds and ends and overhead of development under a
window system and which can be used as a platform for additional development.
In X, the problem is typically solved by using an interactive application
builder tool or by using cut&paste on existing X applications. Good
applications which you might look to manipulate when you want to "test just
this one little thing" include contrib/clients/xskel, a simple R4 program
that puts up a window and allows sketching in it and offers a starting point
for quick hacks, the Xaw examples in the examples/ directory in the X
distributions, and the Xlib "Hello World" example in the R3 doc/HelloWorld
and R4 doc/tutorials/HelloWorld; an updated version of this program which
uses R4 Xlib calls and current ICCCM conventions was posted in 2/90 to
comp.windows.x by Glenn Widener of Tektronix.  [3/90]

In addition, a sample Xt program (for Xaw or Xm) by Rainer Klute showing how
to open multiple displays and how to catch a broken display connection is
available on ftp.x.org in R5contrib/mdisp.tar.Z. [4/92]

A sample multi-display Xt/Xaw program by Oliver Jones is on ftp.x.org in
R5contrib/MultiUserVote.tar.Z. (See also his article in The X Resource, Issue
3, "Multi-User Application Software Using Xt".)