diff --git a/avatica/pom.xml b/avatica/pom.xml
index a65e6c3bb..1389a7700 100644
--- a/avatica/pom.xml
+++ b/avatica/pom.xml
@@ -3,12 +3,12 @@
   <parent>
     <groupId>net.hydromatic</groupId>
     <artifactId>optiq-parent</artifactId>
-    <version>0.6-SNAPSHOT</version>
+    <version>0.6</version>
   </parent>
 
   <artifactId>optiq-avatica</artifactId>
   <packaging>jar</packaging>
-  <version>0.6-SNAPSHOT</version>
+  <version>0.6</version>
   <name>optiq-avatica</name>
   <description>JDBC driver framework.</description>
 
diff --git a/core/pom.xml b/core/pom.xml
index d335e778b..9243ec0ba 100644
--- a/core/pom.xml
+++ b/core/pom.xml
@@ -3,12 +3,12 @@
   <parent>
     <groupId>net.hydromatic</groupId>
     <artifactId>optiq-parent</artifactId>
-    <version>0.6-SNAPSHOT</version>
+    <version>0.6</version>
   </parent>
 
   <artifactId>optiq-core</artifactId>
   <packaging>jar</packaging>
-  <version>0.6-SNAPSHOT</version>
+  <version>0.6</version>
   <name>optiq-core</name>
   <description>Core Optiq APIs and engine.</description>
 
@@ -21,7 +21,7 @@
     <dependency>
       <groupId>net.hydromatic</groupId>
       <artifactId>optiq-avatica</artifactId>
-      <version>0.6-SNAPSHOT</version>
+      <version>0.6</version>
     </dependency>
   </dependencies>
 
diff --git a/mongodb/pom.xml b/mongodb/pom.xml
index ba353969b..c9c7d5c25 100644
--- a/mongodb/pom.xml
+++ b/mongodb/pom.xml
@@ -3,12 +3,12 @@
   <parent>
     <groupId>net.hydromatic</groupId>
     <artifactId>optiq-parent</artifactId>
-    <version>0.6-SNAPSHOT</version>
+    <version>0.6</version>
   </parent>
 
   <artifactId>optiq-mongodb</artifactId>
   <packaging>jar</packaging>
-  <version>0.6-SNAPSHOT</version>
+  <version>0.6</version>
   <name>optiq-mongodb</name>
   <description>MongoDB adapter for Optiq.</description>
 
@@ -20,13 +20,13 @@
     <dependency>
       <groupId>net.hydromatic</groupId>
       <artifactId>optiq-core</artifactId>
-      <version>0.6-SNAPSHOT</version>
+      <version>0.6</version>
       <type>jar</type>
     </dependency>
     <dependency>
       <groupId>net.hydromatic</groupId>
       <artifactId>optiq-core</artifactId>
-      <version>0.6-SNAPSHOT</version>
+      <version>0.6</version>
       <type>test-jar</type>
       <scope>test</scope>
     </dependency>
diff --git a/pom.xml b/pom.xml
index 42c9de39a..0a1acabee 100644
--- a/pom.xml
+++ b/pom.xml
@@ -5,7 +5,7 @@
   <groupId>net.hydromatic</groupId>
   <artifactId>optiq-parent</artifactId>
   <packaging>pom</packaging>
-  <version>0.6-SNAPSHOT</version>
+  <version>0.6</version>
 
   <!-- More project information. -->
   <name>optiq-parent</name>
@@ -79,7 +79,7 @@
     <connection>scm:git:git://github.com/julianhyde/optiq.git</connection>
     <developerConnection>scm:git:git@github.com:julianhyde/optiq.git</developerConnection>
     <url>http://github.com/julianhyde/optiq/tree/master</url>
-    <tag>HEAD</tag>
+    <tag>optiq-parent-0.6</tag>
   </scm>
 
   <modules>
diff --git a/spark/pom.xml b/spark/pom.xml
index 81a502b86..f984a27ca 100644
--- a/spark/pom.xml
+++ b/spark/pom.xml
@@ -3,12 +3,12 @@
   <parent>
     <groupId>net.hydromatic</groupId>
     <artifactId>optiq-parent</artifactId>
-    <version>0.6-SNAPSHOT</version>
+    <version>0.6</version>
   </parent>
 
   <artifactId>optiq-spark</artifactId>
   <packaging>jar</packaging>
-  <version>0.6-SNAPSHOT</version>
+  <version>0.6</version>
   <name>optiq-spark</name>
 
   <properties>
@@ -19,12 +19,12 @@
     <dependency>
       <groupId>net.hydromatic</groupId>
       <artifactId>optiq-core</artifactId>
-      <version>0.6-SNAPSHOT</version>
+      <version>0.6</version>
     </dependency>
     <dependency>
       <groupId>net.hydromatic</groupId>
       <artifactId>optiq-core</artifactId>
-      <version>0.6-SNAPSHOT</version>
+      <version>0.6</version>
       <type>test-jar</type>
       <scope>test</scope>
     </dependency>
diff --git a/splunk/pom.xml b/splunk/pom.xml
index 5a90cafb9..e117cc06a 100644
--- a/splunk/pom.xml
+++ b/splunk/pom.xml
@@ -3,12 +3,12 @@
   <parent>
     <groupId>net.hydromatic</groupId>
     <artifactId>optiq-parent</artifactId>
-    <version>0.6-SNAPSHOT</version>
+    <version>0.6</version>
   </parent>
 
   <artifactId>optiq-splunk</artifactId>
   <packaging>jar</packaging>
-  <version>0.6-SNAPSHOT</version>
+  <version>0.6</version>
   <name>optiq-splunk</name>
   <description>Splunk adapter for Optiq; also a JDBC driver for Splunk.</description>
 
@@ -20,7 +20,7 @@
     <dependency>
       <groupId>net.hydromatic</groupId>
       <artifactId>optiq-core</artifactId>
-      <version>0.6-SNAPSHOT</version>
+      <version>0.6</version>
     </dependency>
     <dependency>
       <groupId>net.sf.opencsv</groupId>