What are some alternatives?
When comparing PortableApps.com and Start10, you can also consider the following products
LiberKey - Portable applications launcher, LiberKey includes 305 portable applications.
Open Shell - Open Shell is a fork of the Classic Shell project for Windows that getting back the classic start...
SyMenu - SyMenu is a portable menu launcher and Start Menu replacement to organize your applications quickly...
StartIsBack - StartIsBack returns Windows 10 and Windows 8 a real fully featured start menu and start button, behaving exactly like the ones in Windows 7. It's totally awesome and easy solution for your new Windows woes.
PStart - PStart is a simple tray tool to start user defined applications.
Classic Shell - Classic Shell was developed for Windows 8 since that was the first version of the popular operating system to forgo the iconic Start menu.