Rename README files to README.txt (and several similar files).

Files without '.txt' suffix can't be handled well by Windows (users),
hence renaming such text files to *.txt makes FLTK more "Windows-friendly".

There are a few exceptions (this is intentional): README and other files
in bundled libraries (maintained upstream) are not changed.

CHANGES.txt

@@ -3,7 +3,7 @@ Changes in FLTK 1.4.0					Released: ??? ?? 2019
   General Information about this Release
 
   - FLTK 1.4.0 is based on FLTK 1.3.4 (released Nov 15 2016),
-    see CHANGES_1.3 for more information.
+    see CHANGES_1.3.txt for more information.
 
   - CMake is the primary supported build system in FLTK 1.4.0 and later.
     CMake can be used to generate Makefiles, IDE project files, and
@@ -168,14 +168,14 @@ Changes in FLTK 1.4.0					Released: ??? ?? 2019
 
 Changes in FLTK 1.3
 
-  See CHANGES_1.3
+  See CHANGES_1.3.txt
 
 
 Changes in FLTK 1.1
 
-  See CHANGES_1.1
+  See CHANGES_1.1.txt
 
 
 Changes in FLTK 1.0
 
-  See CHANGES_1.0
+  See CHANGES_1.0.txt

CHANGES_1.3.txt

@@ -668,9 +668,9 @@ CHANGES IN FLTK 1.3.0					RELEASED: Jun 16 2011
 
 CHANGES IN FLTK 1.1
 
-	See CHANGES_1.1
+	See CHANGES_1.1.txt
 
 
 CHANGES IN FLTK 1.0
 
-	See CHANGES_1.0
+	See CHANGES_1.0.txt

CREDITS.txt

@@ -1,12 +1,12 @@
-CREDITS - Fast Light Tool Kit (FLTK) Version 1.4.0
+CREDITS.txt - Fast Light Tool Kit (FLTK) Version 1.4.0
---------------------------------------------------
+------------------------------------------------------
 
     This file lists the people responsible for the toolkit you are
     now using.  If you've been looking for your name in lights
     but we've forgotten you here, please use the report on the
     following page, and we'll update this file accordingly:
 
-        http://www.fltk.org/str.php
+        https://www.fltk.org/str.php
 
 
 CORE DEVELOPERS

README.IDE.txt

@@ -1,12 +1,12 @@
--------------------------------------------
+-----------------------------------------
-   HOW TO USE THE FLTK IDE ENVIRONMENTS
+  HOW TO BUILD AND USE FLTK WITH AN IDE
--------------------------------------------
+-----------------------------------------
 
-Since FLTK 1.4.0 we do no longer include IDE solution files in our
+Since FLTK 1.4 we do no longer include IDE [1] solution files in our
-source distribution.
+source distribution. [2]
 
 If you want to build the FLTK library with an IDE you need to use
-CMake to generate the IDE files from the source distribution.
+CMake [3] to generate the IDE files from the source distribution.
 
 The FLTK team will officially support generation of selected IDE projects,
 particularly Visual C++ and Xcode. Older version support of these IDE
@@ -21,10 +21,9 @@ need help to adjust the CMake files to fit a particular IDE project.
 Using CMake to generate IDE project files
 ------------------------------------------------------------------------
 
-IDE files can easily be created using CMake and the provided
+IDE files can easily be created using CMake and the provided CMake files.
-CMake files.
 
-For more info about using CMake to build FLTK please read the file
+For more informations about using CMake to build FLTK please read the file
 README.CMake.txt in the root directory of the FLTK distribution.
 
 
@@ -39,3 +38,15 @@ README.CMake.txt in the root directory of the FLTK distribution.
 Note: "Not supported" doesn't mean that a particular generator does not work,
       but the FLTK team does not put much effort into making this IDE work,
       hence it may work for you or not. Contributions welcome.
+
+--------------------------------------------------------------------------------
+
+[1] IDE = Integrated Development Environment,
+    for instance Visual Studio, Xcode, Eclipse, ...
+    https://en.wikipedia.org/wiki/Integrated_development_environment
+
+[2] The only exception is the Android Studio IDE in ide/AndroidStudio3
+    currently provided for testing. This IDE solution is likely to be
+    moved elsewhere or removed entirely before FLTK 1.4 will be released.
+
+[3] https://cmake.org/

documentation/README.txt

@@ -1,12 +1,11 @@
-README (documentation)
+README.txt (documentation)
-----------------------
+---------------------------
 FLTK 1.3 (and higher) documentation is available in HTML and PDF format.
 The documentation must be generated in a separate step or downloaded
 from FLTK's software download pages. The documentation can also
 be accessed online.
 
-To read the docs after downloading or generating them, open the
+To read the docs after downloading or generating them, open the files:
-files:
 
     documentation/html/index.html
     documentation/fltk.pdf
@@ -21,14 +20,14 @@ along with the PDF version of the manual. The docs on the web site
 are usually somewhat older (latest release). Use this URL to find
 the current online documentation:
 
-    http://www.fltk.org/documentation.php
+    https://www.fltk.org/documentation.php
 
 
 Documentation Download:
 -----------------------
 To download pre-generated docs, go to
 
-    http://www.fltk.org/software.php
+    https://www.fltk.org/software.php
 
 and look for the files
 
@@ -42,13 +41,18 @@ did with the source tarball.
 Generation of Documentation (common part):
 ------------------------------------------
 To generate the documentation yourself, you should have Doxygen
-version 1.5.7 or later (recommended version is 1.7.3 or later).
+version 1.8 or later (recommended version is 1.8.13 or later).
+Older Doxygen versions than 1.8 may or may not work.
 
 To generate the PDF version you also need a current version of LaTeX.
 You can use the packages tetex (older) or texlive (current) if your
 distribution provides them. You may need to install additional fonts
 and other sub-packages for the PDF version to be generated correctly.
 
+Note: packages known to work under Ubuntu 18.04:
+
+  texlive texlive-extra-utils texlive-latex-extra texlive-font-utils
+
 
 Generation of Documentation with autoconf (configure) + make:
 -------------------------------------------------------------
@@ -91,10 +95,10 @@ manually, because the generation is not included in the standard ('all')
 target. This may be changed in the future.
 
 
-FLTK Developer Snapshots or Subversion Usage:
+FLTK Developer Snapshots or Git Usage:
----------------------------------------------
+--------------------------------------
 There is no pre-generated documentation available if you use a current
-developer snapshot or subversion. You must generate the documentation
+developer snapshot or git. You must generate the documentation
 yourself or access the online documentation.
 
 
@@ -105,4 +109,4 @@ contribute an example, section, or chapter to the FLTK manual, please
 post a question in the fltk newsgroup fltk.general or post a bug
 report or feature request at:
 
-    http://www.fltk.org/str.php
+    https://www.fltk.org/str.php

documentation/src/intro.dox

@@ -5,7 +5,7 @@
 The Fast Light Tool Kit ("FLTK", pronounced
 "fulltick") is a cross-platform C++ GUI toolkit for
 UNIX®/Linux® (X11), Microsoft® Windows®, and
-Apple® OS X®. FLTK provides modern GUI functionality without the
+Apple® macOS®. FLTK provides modern GUI functionality without the
 bloat and supports 3D graphics via OpenGL® and its built-in
 GLUT emulation. It was originally developed by Mr. Bill Spitzak
 and is currently maintained by a small group of developers
@@ -143,13 +143,10 @@ the toolkit, which was already in use by several people, Bill
 came up with "FLTK", including a bogus excuse that it
 stands for "The Fast Light Toolkit".
 
-\section intro_unix Building and Installing FLTK Under UNIX and Apple OS X
+\section intro_unix Building and Installing FLTK Under UNIX and Apple macOS
 
-In most cases you can just type "make". This will
+In most cases you can just type "make". This will run configure with
-run configure with the default of no options and then compile
+the default of no options and then compile everything.
-everything.
-
-For OS X, Xcode 3 project files can be found in the 'ide' directory.
 
 FLTK uses GNU autoconf to configure itself for your UNIX
 platform. The main things that the configure script will look
@@ -268,37 +265,34 @@ with object files from any of the other environments!
 (They use incompatible C++ conventions internally.)
 
 Free Microsoft Visual C++ 2008 Express and Visual C++ 2010 Express
-or later versions using the supplied workspace and
+or later versions using workspace and project files generated by CMake.
-project files. Older versions, and the commercial
+Older versions and the commercial versions can be used as well, if they
-versions, can be used as well, if they can open
+can open the project files.
-the project files.
 Be sure to get your service packs!
 
-The project files can be found in the "ide/" directory.
+Since FLTK 1.4 the project files MUST be generated with CMake.
-Please read "ide/README.IDE" for more info about this.
+Please read "README.CMake.txt" for more information about this.
 
 
 \subsection intro_cygwin_mingw GNU toolsets (Cygwin or MinGW) hosted on Windows
 
-If using Cygwin with the Cygwin shell, or MinGW with
+If using Cygwin with the Cygwin shell, or MinGW with the Msys shell,
-the Msys shell, these build environments behave very
+these build environments behave very much like a Unix or macOS build
-much like a Unix or OS X build and the notes above in
+and the notes above in the section on
-the section on
+<i>Building and Installing FLTK Under UNIX and Apple macOS</i>
-<i>Building and Installing FLTK Under UNIX and Apple OS X</i>
 apply, in particular the descriptions of using the
 "configure" script and its related options.
 
-In general for a build using these tools, e.g. for
+In general for a build using these tools, e.g. for the Msys shell with
-the Msys shell with MinGW,
+MinGW, it should suffice to "cd" into the directory where you have
-it should suffice to "cd" into the directory where
+extracted the FLTK tarball and type:
-you have extracted the fltk tarball and type:
 
 \code
 ./configure
 make
 \endcode
 
-This will build the fltk libraries and they can then be
+This will build the FLTK libraries and they can then be
 utilised directly from the build location.
 NOTE: this may be simpler than "installing" them in
 many cases as different tool chains on Windows have
@@ -319,7 +313,7 @@ something like "C:\msys\1.0\local\lib", depending
 on where your Msys installation is rooted, which may
 not be useful to other tools.
 
-If you want to install your built fltk libraries in a
+If you want to install your built FLTK libraries in a
 non-standard location you may do:
 
 \code
@@ -328,10 +322,10 @@ make
 \endcode
 
 Where the value passed to "prefix" is the path at which
-you would like fltk to be installed.
+you would like FLTK to be installed.
 
 A subsequent invocation of "make install" will then place
-the fltk libraries and header files into that path.
+the FLTK libraries and header files into that path.
 
 The other options to "configure" may also be used to
 tailor the build to suit your environment.
@@ -354,28 +348,29 @@ header files.
 FLTK is available on the 'net in a bunch of locations:
 
 \par WWW
-http://www.fltk.org/ <br>
+https://www.fltk.org/ <br>
-http://www.fltk.org/str.php [for reporting bugs] <br>
+https://www.fltk.org/str.php [for reporting bugs] <br>
-http://www.fltk.org/software.php [source code]<br>
+https://www.fltk.org/software.php [download source code]<br>
-http://www.fltk.org/newsgroups.php [newsgroup/forums]
+https://www.fltk.org/newsgroups.php [newsgroup/forums]
 
 \par NNTP Newsgroups
 https://groups.google.com/forum/#!forum/fltkgeneral [Google Groups interface]
 news://fltk.org:1024/ [NNTP interface]<br>
-http://fltk.org/newsgroups.php [web interface]<br>
+https://www.fltk.org/newsgroups.php [web interface]<br>
 
 \section intro_reporting Reporting Bugs
 
 To report a bug in FLTK, or for feature requests, please use the form at
-<A href="http://www.fltk.org/str.php">http://www.fltk.org/str.php</A>,
+<A href="https://www.fltk.org/str.php">https://www.fltk.org/str.php</A>,
 and click on "Submit Bug or Feature Request".
 
 You'll be prompted for the FLTK version, operating system & version,
 and compiler that you are using. We will be unable to provide
 any kind of help without that basic information.
 
-For general support and questions, please use the fltk.general newsgroup (see above, "NNTP Newsgroups")
+For general support and questions, please use the fltk.general newsgroup
-or the web interface to the newsgroups at <A href="http://fltk.org/newsgroups.php">http://fltk.org/newsgroups.php</A>.
+(see above, "NNTP Newsgroups") or the web interface to the newsgroups at
+<A href="https://www.fltk.org/newsgroups.php">https://www.fltk.org/newsgroups.php</A>.
 
 \htmlonly
 <hr>

fltk.list.in

@@ -22,7 +22,7 @@
 %copyright 1998-2018 by Bill Spitzak and others.
 %vendor FLTK Development Team
 %license COPYING
-%readme README
+%readme README.txt
 %version @FL_MAJOR_VERSION@.@FL_MINOR_VERSION@.@FL_PATCH_VERSION@
 %description The Fast Light Tool Kit ("FLTK", pronounced "fulltick") is a
 %description cross-platform C++ GUI toolkit for UNIX(r)/Linux(r) (X11),

test/README.txt

@@ -1,5 +1,5 @@
-test/README - 20 Oct 1998
+test/README.txt - 20 Oct 1998
--------------------------
+-----------------------------
 
 This directory contains tests and demos of FL.  In most cases you can
 learn a lot about how to program FL by looking at the source code.
@@ -28,3 +28,8 @@ shiny:		Demo of drawing FL's controls using OpenGL
 forms:		An XForms program to demonstrate emulation
 
 colbrowser:	Another XForms program that is actually useful
+
+
+-----------------------------------------------------
+Note: this file is outdated and incomplete. (*FIXME*)
+-----------------------------------------------------