The package bundle curve2e is composed of the following files

curve2e.dtx
curve2e.pdf
mainfest.txt
README

Manifest.txt is this file.

curve2e.dtx is the documented TeX source file of package curve2e.sty; you get both
curve2e.sty and curve2e.pdf by running pdflatex on curve2e.dtx.

README contains general information

The package has the LPPL status of author maintained.

This package is subject to the LaTeX Project Public Licence, LPPL, version 1.3 or any
successive version.

Therefore, according to the licence, you are entitled to modify this package, 
as long as you fulfil the few conditions set forth by the Licence.

Nevertheless this package is an extension to the standard LaTeX package pict2e 
(2014). Therefore  any change must be controlled  against the parent package 
pict2e so as to avoid redefining what has already been incorporated in the 
official package. 

If you prefer sending me your modifications, as long as I will maintain this
package, I will possibly include every (documented) suggestion or modification 
into this package.

Claudio Beccari

claudio.beccari@gmail.com