unix.stackexchange.com
In short: Getting listed on Unix & Linux Stack Exchange is free. Plan for about 45 minutes — there is material to prepare and a review to wait on.
What they ask for: Answer shell and Linux questions and put your site on your profile.
Answer shell and Linux questions and put your site on your profile.
Disclose any link to your own work.
Open the submission page on unix.stackexchange.com and complete its form — that is the "Open submit page" link at the top of this page.
Disclose any link to your own work.
Priority sets the band — this one is later. Cost (free) and effort (moderate) move it within that band, which puts it in the long tail tier. The score orders a submission queue. It is not a measure of the site’s domain authority, traffic or quality.