-
Ninja showed real promise for a while, but then CMake grew up and people stopped seeing a reason to leave it behind.
-
SaaSHub
SaaSHub - Software Alternatives and Reviews. SaaSHub helps you find the best software and product alternatives
-
Bazel is a Google project that showcases first-class support for the major languages Google uses (C++, Java, Go), and it'd probably have replaced CMake if it weren't written in Java, which brought a host of technical challenges. Then those challenges were fixed and Oracle threatened to bring legal challenges instead.
-
SCons never got popular enough to escape the niches it grew up in.
NOTE:
The number of mentions on this list indicates mentions on common posts plus user suggested alternatives.
Hence, a higher number means a more popular project.