A family of Microsoft relational database management systems designed for ease of use.
Sadly, you can only easily migrate the data, everything else is a complete rewrite! So, no, no easy flip a switch and you're done. It was almost a year (although there were some major additions made). It has also offered a new world of tools, things that couldn't be done before and now is accessible from anywhere in the world as long as you have a browser.
In this specific case, I went the route of using MySQL/PHP (with a framework) and everything else that it entails (html, css, javascript/jQuery, bootstrap, ...). I will say it was challenging at times, but very rewarding and the final product exceeds my client's expectations. So far, there has only been one area that is problematic, I can't automate Outlook. I can generate e-mails, no issue there, but I can't start an e-mail and display it to the user for review/completion. I've created a form with the elements (subject, body, ...), but it isn't exactly the same. So far, that has been the only true issue. Beyond that I have been able to everything I previously did and more.