1. A method for trading quotes relating to financial instruments received from quoting firms in a computerized trading system having a plurality of independent trading environments, the method comprising: providing a plurality of independent trading environments, wherein providing each independent trading environment comprises: providing a communication network; providing a matching engine executed by a server, wherein the matching engine accesses a shared memory; providing a plurality of interface applications, executed by the server, wherein each interface application is associated with a particular quoting firm; and assigning areas of the shared memory to each of the plurality of interface applications; receiving quotes from the plurality of quoting firms at their respective interface applications, wherein the received quotes comprise data representing at least one of offers to buy and offers to sell a financial instrument; placing, by the interface applications, the quotes received from the respective quoting firms in their respective assigned areas of the shared memory; matching, by the matching engine, the received quotes placed in the areas of the shared memory, wherein the matching comprises: polling, by the matching engine, a first area of memory to find a quote or quotes; processing the quote or quotes in the first area, the processing including searching for a matching contraside interest, allocating the resulting matching interest according to at least one allocation rule, and executing the quote according to the allocating; and repeating said polling and processing for each area of the shared memory in a round robin manner; and the matching engine, upon completion of polling all areas of the shared memory, checking a network port of the matching engine to receive messages from the network, the messages comprising at least one of data representing a state of a financial instrument market and data representing incoming orders for financial instruments, before repeating said matching procedure.