Why do we have those notes here? Half-Life must be played via Steam, non-Steam means in essence pirated. It'd be like including save game location dirs with 'SKIDROW' in the path (which a lot of websites do...).
Topic on Talk:Half-Life
The original Retail version came out 5 years before Steam, thus there are versions that don't require Steam.
I'm well aware of that. However, every CD-key was redeemable on Steam later. There is absolutely no reason to use the non-Steam version, which is severely outdated, especially after the recent wave of fixes.
I've removed those sections now. Since all are redeemable on Steam, I see no reason not to use it.