Usually an operating system’s installation media grows from one release to the next release as they add more features.
The DragonFly BSD team is working in reducing of ISO image size by reducing the size of packages on the operating system’s media.
The next release of DragonFly BSD ISO image size should be smaller.
They have removed enough packages on the installer image to drop the package disk usage 50%.
How it can be done?
The DragonFly BSD Team has removed multiple packages from /usr/local, which are no more needed for them.
After removing multiple packages from /usr/local, this commit cuts the number of installed packages from 40 to 22 and reduces /usr/local’s size from 300M to 145M.
If you would like to know how it was done technically?
The details can be found in their mailing list post.