substantial market for Business to Business (B2B) integration tools such as Enterprise  Application  Integration  (EAI),  messaging  software,  and  other middleware solutions. The  Internet  exposed  this  problem  even  more  as  organizations attempted to link their businesses and systems in support of new initiatives such as collaboration, partner relationship management, product life cycle management, and other emerging business needs. Business strategies such as  M&As  drove  a  need  to  rapidly  integrate  an  acquired  organization’s business processes and IT systems. Issues such as master data management, managing  customer  and  product  information,  and  eliminating  redundant systems have plagued businesses in M&A mode. Productivity gains were sought through initiatives such as employee self-service and enterprise por- tals, which made it easier to access relevant information by role and needs. B2B  collaboration  has  to  date  been  inhibited  by  expensive  integration efforts,  inflexible  enterprise  business  applications,  and  the  inability  to extend  and/or  augment  existing  business  applications  to  accomplish  new business functions as business needs change. The Enterprise Application Phenomenon The  enterprise  application  phenomenon  is  the  culmination  of  the  client- server era of computing. Client-server computing based on the three-tier, then the n-tier architecture, completely revolutionized computing as it was known in the early 1990s. Client-server computing models broke the para- digm  of  large  centralized  mainframes  serving  masses  of  dumb  terminals based on the dramatic rise of the Personal Computer (PC) in corporate and home  computing.  Client-server  computing  hailed  the  introduction  of  the distributed  computing  model,  where  applications  could  be  built  and deployed  more  efficiently  and  targeted  to  distinct  business  audiences, departments,  and  end  users,  as  opposed  to  being  driven  by  internal  IT organizations  that  were  the  traditional  buyers  of  computer  applications. The client-server architecture created new “markets” for software vendors to sell to by virtue of the increasing development of departmental and func- tional  applications  that  solved  targeted  business  problems,  yet  interacted with other functional applications or modules from the same vendors. SAP R/3  arguably  represents  the  pinnacle  of  client-server  success.  This  ERP solution is the industry’s leading business computing platform, followed by offerings from Oracle, PeopleSoft, and a host of others. SAP’s dominance in the ERP arena can be explained by a number of factors, but one surely is that  it  was  among  the  first  business  application  suites  to  be  built  on  a client-server  architecture.  When  SAP  R/2,  the  mainframe  version,  was replaced  by  its  R/3  client-server  release,  SAP  took  off  and  never  looked back. SAP rolled over all the competitors in the ERP space and established 10 EXECUTIVE’S GUIDE TO WEB SERVICES 74188_WY_Marks_01  2/5/2003  4:08 PM  Page 10