$ brew tap homebrew/versions
==> Tapping Homebrew/versions
Cloning into '/usr/local/Library/Taps/homebrew/homebrew-versions'...
remote: Counting objects: 3670, done.
remote: Compressing objects: 100% (36/36), done.
remote: Total 3670 (delta 17), reused 0 (delta 0), pack-reused 3634
Receiving objects: 100% (3670/3670), 1.20 MiB | 577.00 KiB/s, done.
Resolving deltas: 100% (2123/2123), done.
Checking connectivity... done.
Tapped 218 formulae (241 files, 2.4M)

$ brew search solr
php53-solr  php54-solr	php55-solr  php56-solr	solr	    solr14	solr36	    solr4

$ brew install solr4