NEW YORK – Salesforce.com plans to unveil next month an application building system, dubbed Sforce, to offer customers new integration and customization options.Salesforce.com, in San Francisco, is the most visible of several ASPs (application service providers) selling customers access to enterprise software such as CRM (customer relationship management) systems, hosted and maintained by the vendor in exchange for a monthly fee. With its price tag starting at $65 per user, per month, four-year-old Salesforce.com is operating profitably, with revenue of $60 million last year, company executives told research firm Aberdeen Group.Microsoft, Sun Microsystems, Borland Software and BEA Systems participated in the development of Sforce, according to Salesforce.com, which declined to discuss the product in detail in advance of a scheduled June 3 launch event, in New York. Software Development