Maybe only the 5 in this Perl is eternal. Once in a while some generous souls polish the gem to maintain and extend it and the subversions increment. Observe perldelta-5.28.0 (now with Unicode 10)!

There are 6 evolutionary expressions of Perl, two in active development and use, and four vintages (some known to still be in use) waiting for someone to plug in Unicode 10 or something because they are probably lean, mean text-processing machines that would enjoy being embedded in some RPi an droids:

Perl 1.0_16        2003-Dec-18
Perl 2.001         1988-Jun-28
Perl 3.044         1991-Jan-12
Perl 4.036         1993-Feb-05     Very stable.
Perl 5.28.0        2018-Jun-23
Perl 6             2015-Dec-25

Perls are just waiting to be tossed at unsuspecting and grateful software consumers. It's not like people care how their apps work. For example I have never installed Python on purpose but there are 6 versions of the thing with stuff like Tcl and Wx installed on my laptop. Anyway my favorite IDE seems to function by running python scripts behind some fancy wxwidgets to highlight and eval perl code in real time! I guess they make money by giving it away to people and selling it to businesses. I think that can be done in Perl with some CPAN modules too. I mean something impressive with Devel::REPL glued to PPI feeding Text::Highlight with real-time Perl::Critic, RegExp::Debugger, Pod::Simple, NYTProf etc. with a Tcl::Tk or HTML/Javascript GUI all packed into something that installs with one click and starts with two. My next project, and maybe yours... ;-)