Many Webforms developers are resistant to Monorail and for various reasons. I would guess that the second biggest reason, behind simple intertia, is the perceived lack of rich UI components. Recently Ayende decided to do something about it by adding a Castle.MonoRail.ViewComponents to Castle Contrib. It’s a place to aggregate view components that might be generally useful to Monorail UI development.
I have recently created ColumnChartComponent and added it to CastleContrib. ColumnChartComponent renders fairly basic column charts. (By “column chart” I mean charts with vertical bars.) Check it out. I hope you like it and find it useful!