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+Tcllib installation directory layout
+====================================
+
+This document describes the possible layouts for an installed tcllib,
+discusses their pro and contra and makes a choice for Tcllib 1.4. A
+roadmap of changes in the future is made available as appendix.
+
+[L1/D] Deep layout
+------------------
+
+        This is the layout of Tcllib 1.3 (and versions before that).
+
+        A single directory tcllib<version> is created, and all
+        subdirectories of the 'modules' subdirectory in the
+        distribution is copied into it. This is restricted at large to
+        *.tcl files, with exception made for some modules with special
+        needs.
+
+        Pro:
+        Contra:
+                Makes the handling of the various package indices,
+                well, not difficult, but uncomfortable.
+
+
+[L2/Fa] Flat layout 1
+---------------------
+
+        A directory is created for each module of tcllib.
+
+        Pro:
+                Handling of package indices is easier than for L1/D, a
+                toplevel index file with all its problems is not
+                required anymore.
+
+        Contra:
+                Directories should be versioned to avoid conflicts
+                between multiple releases. modules have no
+                version. This can be faked for modules containing one
+                package, but not for the modules with more.
+
+
+[L2/Fb] Flat layout 2
+---------------------
+
+        A directory is created for each package in tcllib.
+
+        Pro
+                Handling of package indices is easy, one per package.
+
+        Contra:
+                Modules containing more than one package are difficult
+                to handle. The system has to split them into the
+                individual packages. This rendered very difficult
+                because of shared package index files.
+        
+                This can be solved by moving tcllib (back) towards of
+                one package per module. When that goal is reached
+                L2/Fa and L2/Fb become the same, and the contra for
+                L2/Fa vanishes too as an exact version number can be
+                associated with each directory.
+
+Chosen layout for Tcllib 1.4
+----------------------------
+
+        L1/D
+
+        Despite the problems with package indices the contras against
+        the flat structures are too strong at this point in
+        time. Automatic solutions are not really possible, or require
+        a very high effort.
+
+Roadmap
+-------
+        Change the module directories of tcllib to contain exactly one
+        package per directory, with appropriate index (and meta data).
+
+        This not only makes sense for easier handling of installation
+        and package indices, but also in the greater context of
+        wrapping code for deployment.
+
+
+-----------------------------------
+This document is in the public domain.
+
+                        Andreas Kupries <andreas_kupries@users.sf.net>