Uploadify (HTML5 + Flash) is a control that allows the integration of single (or multiple) file uploads on your website. It can be easily customized, for instance, the maximum file size for each upload and file-type you would like to allow for upload can be configured in the control's properties. The flash version is based on Uploadify project which is one of the most used upload control in web applications.
The control saves the uploaded file in the folder defined as "temporal media directory" in GeneXus (PrivateTempStorage) like the Blob data type and it also uses a temporal name (to avoid overlap).
For more information visit: Ignia Framework Documentation