ReqText is a VirtueMart plugin to add the functionality of required user input fields for a product. This is a feature the current version of VirtueMart does not have.
Now you can add textinput and textarea fields to products. It's also possible to add checkboxes, radiobuttons and dropdown list which user must select before adding a product to the cart.
This plugin does not alter any source code of the VirtueMart package or it's plugins. You can update VirtueMart at any time without the loss of the ReqText plugin functionality.