Repology - Multiple package repositories analyzer
Anitya - A software release monitoring project.
DistroWatch - 9 hours ago - It does include a proprietary software set optimized for business users, students, researchers and developers." A list of features and further details can be found in the company's release announcement.
DistroHunt - Donation-based and video-focused directory of Linux distributions
Versionfeeds - Custom RSS Feeds for Releases of your favorite Software
Freshcode - freshcode.club attempts to substitute ...