FTDNA is the only firm that posts project results publicly. This is a fairly recent change. Many of the projects based there used (and still use) private sites or WorldFamilies.net, which allows posting of results from any firm.
DNAHeritage went out of business and transferred all results, except opt-outs, to FTDNA.
Ancestry is the only other firm with surname pages. However, they are no longer testing Y- and mtDNA and will shut down the website in September. The only way to get to the surname tables was to join a surname project (testing there not required) or find private sites. Many people will transfer their results to FTDNA.
Genebase.com seems to have only database matching and seems to require testing there to use it.
SMGF.org quit testing, but its database is free and is being maintained by Ancestry.
Y-Search.org has a lot of entries from other firms.