INFR1 was founded by Woomeister using lots of assets from Over The Top campaign. As OTT was never released, some OTT ships like SCv Scylla saw action in INFR1 for the first time.
Sol: A History is basicly portrayal of Earth Alliance history made by 3rd Party, and outside Inferno Team. Although appreciated by official Inferno team, and upgraded by one of Inferno team members - Admiral Nelson, it is non-canon for official Inferno timeline.
There was an old campaign with EA as player's faction and Nightmares as main antagonists - the Solar Wars
. It was completely unplayable. If I remember correctly, the first mission got stuck after introduction chatter.
Ghost Revenants campaign was basicly made using modified Inferno modpack, and share majority of ships and weapons with Inferno.
Procyon Insurgency introduced Ancient ships from INFR1.
Shadow Genesis inherited some ship designs, including Icelus, Boreas and Phobos Advanced remodelled into new destroyer class - GTD Nephelai.
Dawn of Sol inherited lots of ships from INFR1, and adapted them to various solar factions.