Yes, you can use SPDocKit on Sharepoint 2007 and 2010. However, there are feature differences in SharePoint 2010 that are not offered in SharePoint 2007. Please go to the following link to compare these differences.
The product uses the SharePoint Server Object Model to retrieve information about your farm and it needs to run on the SharePoint server to be able to make API calls. Users running the software need to have proper privileges to do so. Click here to learn more.
For more details check our system requirements page.
Hardware requirements are the same as the requirements for the underlying operating system. When running and loading farms, the application can use up to 200 MB RAM.