Yes. RSLinx Classic (originally just called RSLinx) was originally developed when the PLC-5 and SLC 500 were the height of Allen-Bradley technology. Back then we had a lot of dedicated hardware for talking to proprietary networks. You used RSLinx to create a driver base don the hardware you were plugging into your PC. So there were several Ethernet options, several DH+ option, several DeviceNet and ControlNet options. They did of course make it work with older PLC-2 and PLC-3 systems (though those systems never had Windows software). And naturally they made it work with the new "Logix" controllers. But at its core, it was built for PLC-5/SLC 500. And they later had versions that supported DDE and OPC communications, but those capabilities were an added cost.
When Rockwell came out with their FT View products, they introduced a whole new scheme for getting data into and out of these systems. And, they wanted to optimize it for use with their newer "Logix" style controller. They decided that they would use something similar to OPC. FactoryTalk LiveData was the end result.
RSLinx Classic supported OPC, but they were charging people for that. They needed something they could include in the View platform without devaluing their existing paid product. So they came out with RSLinx Enterprise, and the original RSLinx product was renamed RSLinx Classic. Enterprise was designed/optimized for the Logix controllers, but it could still talk with the older legacy systems as well.
The Enterprise name implies that it is "more" than the newly renamed RSLinx Classic, but it was in reality less. Enterprise was simply a glorified OPC server for this LiveData for the View platform. You still needed Classic whenever you wanted to go online with a PLC from your laptop. Enterprise couldn't do any of that for us.
Fast forward to today, and RSLinx Enterprise is now FactoryTalk Linx, and it can now handle other tasks beyond being just an OPC server. Beyond just LiveData, I can now use it to go online with my Logix controller. I can use it to perform firmware updates. I can use it to get alarm data.
We live in a largely Ethernet world these days. We don't need dozens of different proprietary interfaces anymore. FT Linx can't handle some of the oddball configurations we used to have to use to be able to talk on older networks with older hardware. If my plant still has a bunch of SLC 500 controllers, then I still need RSLinx Classic. But the need for RSLinx is getting less and less all the time. And I doubt FT Linx will ever be a complete replacement for RSLinx Classic.
I have probably over-simplified some of this, and may have mixed some things up here. But hopefully that helps to clarify why these two separate products exist.
Oh, and they probably don't mention RSLinx on the page you talked about because it is an old product and they want people to move away from it. If I go to their product page, there is no mention of RSLogix 5 or RSLogix 500. If I dig a little, I can find them though. And remember RSLinx Classic on its own is kind of useless. You use it with something else, like RSLogix 5/500/5000.
OG