What RDBMS have you used extensively, or are at least somewhat familiar with based on first-hand experience?

Jules Bohanon, Lakeland, Florida:
     SQL. On occasion mySQL if I'm taking over an existing project, but I'd never choose it.

Assem Bayahi, Mourouj 1, Tunisia:
     MySQL

Md. Obaidul Haque Sarker, Dhaka, Bangladesh:
     I worked with Oracle RDBMS in mostly in my service tenure. But I also worked with other RDBMS like MSSQL, MySQL, PostgreeSQL, Sysbase and DB2.

Ehtisham Rasheed, Sialkot, Pakistan:
     im comfortable with both Access and SQL Server...

Mark Horner, Bristol, England:
     What RDBMS have you used extensively, or are at least somewhat familiar with based on first-hand experience? Access all the way, some class it as just a DBMS but in an office environment with a split front-end and back-end it’s definitely worthy of a RDBMS title.

Ven Grollmus, George Town, Tasmania, Australia:
     The main RDBMS that I have used extensively are Microsoft Access and SQL Server 7, 2000 and 2005.

Bruce Bray, Phoenix, Arizona:
     SQL Server has been my bread and butter for sure. And since Microsoft starting distributing end user versions so that the customer doesn't have to pay full price, it is easier to use than ever.

Yuriy Sultanaev, Ufa, Russia:
     MS SQL server, MS Access, Oracle 11g Apex, PostgreSql, MySQL.

Temitayo Ilori, Berea, Ohio:
     MS Access and Oracle Database

Biju John, Pathanamthitta Dist., Kerala, India:
     MS Access, MySql, MSSql and FoxPro

Grace Elaiza Seballos, Davao City, Philippines:
     Back in college, most of what was used in school was MS Access. In my OJT, we were using Firbird SQL for 2 years. And then we shifted to MS SQL. And we also had clients using Oracle. On 2008, I was exposed with MySQL (innodb engine). Since 2010, most of my clients are either using MS SQL or MySQL. But it wouldn't really matter in my opinion. I only use functions that are available on these 3 RDBMS (MS SQL, MySQL and Oracle).

Artiben prashantbhai S., Bhavnagar, India:
     Microsoft Access