Inline Related Data
A grid row can show more than its own record. GridRelatedRecordsColumn lists the records related to each row — here each account's contacts and opportunities — loaded in one query for the whole page rather than one per row, searchable with the grid's search box, and exported with the rest of the grid.
Accounts with Their Contacts and Opportunities
The contacts are listed by name, each a link to the contact's page. The opportunities are summed up instead: a CellTemplate counts each account's opportunities by status — open, won and lost. Search for a contact's name to find their account. The grid scrolls infinitely, loading the next accounts as you reach the end.