Microsoft's next-generation forms technologies for SharePoint Server 2016 and SharePoint Online seem to have hit a stall, if not a dead end.

InfoPath Forms Services for SharePoint Server 2013 will be supported until April 2023. InfoPath Forms Services in Office 365 will be supported until further notice.

I have been reading and playing with Infopath forms in SharePoint 2010. I have managed to get it to work in a couple of ways, however basic. One way is to create a forms library and upload a form ...

While it supports some basic Forms Based Authentication operations, SharePoint lacks many of the features necessary to properly use FBA. Projects such as the SharePoint 2013 FBA Pack by Chris ...

Creating connectable Web Parts is a good thing for you and your users -- and the default interfaces that come with SharePoint form the architecture you should use to create those Web Parts.