Providing temporary use of on-line non-downloadable software for accessing a financial exchange; providing on-line non-downloadable software for generating cryptographic keys for receiving and spending crypto assets; providing temporary use of on-line non-downloadable software for use in financial trading, clearing, confirmation, and financial trading risk management; providing temporary use of on-line non-downloadable software for accessing financial information and trading of financial instruments; providing temporary use of on-line non-downloadable software for financial trade allocation, confirmation, clearing and settlement transactions; providing temporary use of on-line non-downloadable software for calculating and analyzing prices of financial instruments and accessing financial securities pricing data; providing temporary use of on-line non-downloadable computer software for accessing financial securities pricing data; application service provider featuring application programming interface (API) software; application service provider featuring customizable application programming interfaces (API) for use in building software applications; application service provider featuring application programming interface (API) software for accessing financial information and trading of financial instruments