In my research i have to quote quite often ancient Greek sources, therefore I need a program that can help me with this.

Any suggestions as for a free downloadable program for writing polytonic Greek with aspirations and iota subscripta.

I’ve used UniGreek. See if you like it.

it says the page not available

FWIW,

If you do a yahoo search on, “Unigreek” a number of other choices come up.
The link that leads to the site “metacpan” has some sort of downloadable.
Check them out but my kindle makes saving and reposting links a chore so
You will have to do your own legwork.

Hope this helps,
Cathexis

microsoft also have a politonic keyboard, you could download and use it, it’s not so practical to use but you could get familiar with it and finally as I did, you type in greek without any deal.

εὐψύχει!

I have found keyman