 DragonFly originally used the FreeBSD Ports collection as its official package management system , but starting with the 1 @.@ 4 release switched to NetBSD 's <unk> system , which was perceived as a way of lessening the amount of work needed for third @-@ party software availability . Eventually , maintaining compatibility with <unk> proved to require more effort than was initially anticipated , so the project created <unk> , an overlay on top of the FreeBSD Ports collection . 
