Inline Controls No Longer in Kentico 8?

Can't find that either, but if you go to Sites/Assigned Objects, you have an inline controls tab where you can assign inline controls to your site. Other than that, I couldn't find any place to register new ones, or use them.

When I viewed the Inline Controls module and found the visibility is set to SystemContext.DevelopmentMode. This looks like something that is for Kentico only. If you go to Modules and select the CMS module, expand Administration, expand Development then select Inline controls and click the "Customize" button at the top, you can remove that value from the Visibility condition and it will be available when you refresh the whole page again.

I've submitted a ticket to Kentico regarding this.

I think I figured it out. When I went to look at the location that Brenden mentioned I noticed it said in the description that inline controls are now obsolete and to use inline widgets instead. I searched the docs for inline widgets and found these references: https://docs.kentico.com/display/K8/Adding+page+content+through+widgets#Addingpagecontentthroughwidgets-Addinginlinewidgetsintotext and https://docs.kentico.com/display/K8/Configuring+permissions+for+widgets. So it looks like we need to do something different for inline controls now.

Yes you beat me to it. I don't use inline controls so I wasn't aware they were obsolete. The v7 docs state they are obsolete as well. A widget is simply a scaled back instance of a web part. So if you can create a web part you can create a widget.