I have been developing Excel applications for 6 years. Creating Scheduling, Invoicing, Estimating, HR & CRM applications with Excel exclusively. As my applications and customer needs get larger i have been running into some headaches with Excel as a database. Customers want to share workbooks and simultaneos changes, however as many of us know Excel's Shared Workbook feature leaves a lot to be desired, especially with applications congaing a lot of vba coding (no protect/protection, no advanced filters, no merge/unmerging of cells, No VBA Access while in protection mode, etc). Shared workbook is also causing data loss for some of my customers. While I'm slightly familiar with external databases, I am hesitant to use this as I need a simple solution for my customers and future development of my applications. What is the best way to go in this instance? What skills should I learn to get to the next level of application development? Thanks so much for your feedback.