Have I made a horrendous mistake?

I've been writing a program in J#, since it looked like a really great
language, made development nice and easy, and had features particularly
suited to my application. This program is intended to be given away free,
potentially to millions of users.

But am I correct in my (recently acquired) understanding that in order for a
J# program to run on a computer the computer has to have a "J#
Redistributable" package, and that that package subsequently requires the
".NET Redistributable" or some such thing? And that those add up to over 6
Megabytes of code?

Is this true?

If it is, does anyone have suggestions as to how I might proceed, so tha my
potential users don't have to download obscenely large "redistributable"
packages?

- Roger