- I remember studying and even working on RPC , which was considered to be so cool that in mid-late 90's the technology Giants had Distributed Computing Environment softwares which had services running all over and all you need to do is tell what service you want , remotely. (btw, Remote Procedure Calls - which are very much used even today in distributed file system etc)

- Then, Java picked up its fad, up came RMI (Remote Method Invocation) - it said platform independent service at your desk ... use RMI

- COM/DCOM.. followed with CORBA ( hot technologies with great paychecks once)

In between the two was ASP (Application Service Provider) - which I feel had a lot of Cloud essence

- SaaS (Software as a Service) in LAN

- SaaS (Software as a Service) in internet - up comes Cloud.

Similar we began with MainFrames -> Client Server Models --> Mutiple Server based solutions --> Thick clients based solutions --> <Starts looking messy with cost/power/carbon foot print/ROI> ->consolidate -> virtualize -> centralize --> up comes Cloud --> Mainframes  :-)

So if I summarize the above , I really don't see great invention in technology , but yeah probably good innovation with times and better business models.

laters

Sandeep