The current release version of gnuplot is 4.4.4 (12 November 2011).
Release notes are in file announce-4.4.4
gnuplot.pdf is the User Manual.

Binary packages for Windows:
    gp444win32.zip       Windows binary package
    gp444win32x11.zip    Cygwin (x11) binary package
    gp444dj2.zip         DJGPP binary package

The development version (4.5) can be obtained through CVS.

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