What tool and how to make this?

[Nzkiwis]

I'm looking for a how to guide and advic on eBay advice on what tool to use to create this effect from scratch?

[link removed — please use Insert Image button (mountain and sun) to insert image]

ideally final result svg or something web based as that's where it would be used 

[edit made as per OP's following post]

[Nzkiwis]

Sorry auto correct failed there, should read "advice on what "