diff --git a/pom.xml b/pom.xml
index b998353..46a49e7 100644
--- a/pom.xml
+++ b/pom.xml
@@ -67,19 +67,19 @@
     <dependency>
       <groupId>com.google.code.gson</groupId>
       <artifactId>gson</artifactId>
-      <version>2.10</version>
+      <version>2.10.1</version>
     </dependency>
     <!-- logging framework -->
     <dependency>
       <groupId>ch.qos.logback</groupId>
       <artifactId>logback-classic</artifactId>
-      <version>1.4.4</version>
+      <version>1.4.14</version>
     </dependency>
     <!-- roaring bitmap -->
     <dependency>
       <groupId>org.roaringbitmap</groupId>
       <artifactId>RoaringBitmap</artifactId>
-      <version>0.9.35</version>
+      <version>1.0.1</version>
     </dependency>
   </dependencies>
 
@@ -91,7 +91,7 @@
     <plugin>
       <groupId>org.apache.maven.plugins</groupId>
       <artifactId>maven-source-plugin</artifactId>
-      <version>3.2.1</version>
+      <version>3.3.0</version>
       <executions>
         <execution>
           <id>attach-sources</id>
@@ -104,7 +104,7 @@
     <plugin>
       <groupId>org.apache.maven.plugins</groupId>
       <artifactId>maven-javadoc-plugin</artifactId>
-      <version>3.4.1</version>
+      <version>3.6.3</version>
       <configuration>
         <!-- diable for now for travis: https://github.com/joel-costigliola/assertj-core/issues/1403 -->
         <skip>true</skip>
@@ -121,7 +121,7 @@
     <plugin>
       <groupId>org.apache.maven.plugins</groupId>
       <artifactId>maven-gpg-plugin</artifactId>
-      <version>3.0.1</version>
+      <version>3.1.0</version>
       <executions>
         <execution>
           <id>sign-artifacts</id>
@@ -156,7 +156,7 @@
         <plugin>
           <groupId>org.apache.maven.plugins</groupId>
           <artifactId>maven-release-plugin</artifactId>
-          <version>3.0.0-M7</version>
+          <version>3.0.1</version>
           <configuration>
             <autoVersionSubmodules>true</autoVersionSubmodules>
             <useReleaseProfile>true</useReleaseProfile>
@@ -168,7 +168,7 @@
         <!-- Maven compiler plugin -->
         <plugin>
           <artifactId>maven-compiler-plugin</artifactId>
-          <version>3.10.1</version>
+          <version>3.12.1</version>
           <configuration>
             <release>17</release>
           </configuration>
@@ -178,7 +178,7 @@
         <plugin>
           <groupId>org.apache.maven.plugins</groupId>
           <artifactId>maven-javadoc-plugin</artifactId>
-          <version>3.4.1</version>
+          <version>3.6.3</version>
           <configuration>
             <!-- diable for now for travis: https://github.com/joel-costigliola/assertj-core/issues/1403 -->
             <skip>true</skip>
@@ -199,14 +199,14 @@
         <plugin>
           <groupId>org.apache.maven.plugins</groupId>
           <artifactId>maven-surefire-plugin</artifactId>
-          <version>3.0.0-M7</version>
+          <version>3.2.3</version>
         </plugin>
 
         <!-- License header plugin -->
         <plugin>
           <groupId>org.codehaus.mojo</groupId>
           <artifactId>license-maven-plugin</artifactId>
-          <version>2.0.0</version>
+          <version>2.3.0</version>
           <configuration>
             <organizationName>AgentsOZ</organizationName>
             <copyrightOwners>by its authors. See AUTHORS file.</copyrightOwners>
@@ -269,7 +269,7 @@
         <plugin>
           <groupId>org.jacoco</groupId>
           <artifactId>jacoco-maven-plugin</artifactId>
-          <version>0.8.8</version>
+          <version>0.8.11</version>
           <configuration>
             <excludes>
               <exclude>io/github/agentsoz/jill/util/SparseBitSet*</exclude>
@@ -333,22 +333,22 @@
           <version>3.20.0</version>
           <configuration>
             <skipEmptyReport>false</skipEmptyReport>
-            <linkXref>true</linkXref>
-            <sourceEncoding>utf-8</sourceEncoding>
-            <minimumTokens>100</minimumTokens>
-            <excludes>
-              <exclude>**/*RegressionTest*.java</exclude>
-            </excludes>
-            <excludeRoots>
-              <excludeRoot>target/</excludeRoot>
-            </excludeRoots>
-            <rulesets>
-              <ruleset>${rootdir}/ruleset.xml</ruleset>
-            </rulesets>
-          </configuration>
-        </plugin>
+          <!--<linkXref>true</linkXref>-->
+          <!--<sourceEncoding>utf-8</sourceEncoding>-->
+          <minimumTokens>100</minimumTokens>
+          <excludes>
+            <exclude>**/*RegressionTest*.java</exclude>
+          </excludes>
+          <excludeRoots>
+            <excludeRoot>target/</excludeRoot>
+          </excludeRoots>
+          <rulesets>
+            <ruleset>${rootdir}/ruleset.xml</ruleset>
+          </rulesets>
+        </configuration>
+      </plugin>
 
-        <!-- Checkstyle code style checker  -->
+      <!-- Checkstyle code style checker  -->
         <plugin>
           <groupId>org.apache.maven.plugins</groupId>
           <artifactId>maven-checkstyle-plugin</artifactId>
@@ -386,7 +386,7 @@
       <plugin>
         <groupId>org.apache.maven.plugins</groupId>
         <artifactId>maven-jxr-plugin</artifactId>
-        <version>3.3.0</version>
+        <version>3.3.2</version>
       </plugin>
       <plugin>
         <groupId>org.apache.maven.plugins</groupId>