diff --git a/build-tools/customchecks/src/com/google/gwt/checkstyle/CustomRegexpHeaderCheck.java b/build-tools/customchecks/src/com/google/gwt/checkstyle/CustomRegexpHeaderCheck.java
new file mode 100644
index 0000000..f08a2bd
--- /dev/null
+++ b/build-tools/customchecks/src/com/google/gwt/checkstyle/CustomRegexpHeaderCheck.java
@@ -0,0 +1,215 @@
+/*
+ * Copyright 2011 Google Inc.
+ * 
+ * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except
+ * in compliance with the License. You may obtain a copy of the License at
+ * 
+ * http://www.apache.org/licenses/LICENSE-2.0
+ * 
+ * Unless required by applicable law or agreed to in writing, software distributed under the License
+ * is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express
+ * or implied. See the License for the specific language governing permissions and limitations under
+ * the License.
+ */
+// //////////////////////////////////////////////////////////////////////////////
+// checkstyle: Checks Java source code for adherence to a set of rules.
+// Copyright (C) 2001-2005 Oliver Burn
+//
+// This library is free software; you can redistribute it and/or
+// modify it under the terms of the GNU Lesser General Public
+// License as published by the Free Software Foundation; either
+// version 2.1 of the License, or (at your option) any later version.
+//
+// This library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+// Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public
+// License along with this library; if not, write to the Free Software
+// Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+// //////////////////////////////////////////////////////////////////////////////
+package com.google.gwt.checkstyle;
+
+import com.puppycrawl.tools.checkstyle.checks.header.RegexpHeaderCheck;
+import com.puppycrawl.tools.checkstyle.api.DetailAST;
+import com.puppycrawl.tools.checkstyle.api.Utils;
+
+import org.apache.commons.beanutils.ConversionException;
+
+import java.util.Arrays;
+import java.util.regex.Pattern;
+import java.util.regex.PatternSyntaxException;
+
+/**
+ * Custom version of {@link RegexpHeaderCheck} that has hooks for a custom log handler (see
+ * {@link CustomLogHandler}).
+ * <p>
+ * This is an exact copy of {@link RegexpHeaderCheck} with three exceptions:
+ * <ol>
+ * <li>{@link CustomLogHandler} has been added for custom log callbacks.</li>
+ * <li>{@link #doChecks(CustomLogHandler)} has been added for custom checks. This method is an exact
+ * copy of {@link RegexpHeaderCheck#beginTree(DetailAST)} except all log calls have been replaced
+ * with a call to a custom log handler.</li>
+ * <li>{@link #beginTree(DetailAST)} has been refactored to call
+ * {@link #doChecks(CustomLogHandler)}.
+ * </ol>
+ */
+public class CustomRegexpHeaderCheck extends RegexpHeaderCheck {
+  /**
+   * Custom log handler callback.
+   */
+  abstract static class CustomLogHandler {
+    abstract void log(int aLine, String aKey);
+
+    abstract void log(int aLine, String aKey, Object aObject);
+  }
+
+  // empty array to avoid instantiations.
+  private static final int[] EMPTY_INT_ARRAY = new int[0];
+
+  // the header lines to repeat (0 or more) in the check, sorted.
+  private int[] mMultiLines = EMPTY_INT_ARRAY;
+
+  // the compiled regular expressions
+  private Pattern[] mHeaderRegexps;
+
+  /**
+   * {@inheritDoc}
+   */
+  public void beginTree(DetailAST aRootAST) {
+    doChecks(new CustomLogHandler() {
+      @Override
+      void log(int aLine, String aKey) {
+        CustomRegexpHeaderCheck.this.log(aLine, aKey);
+      }
+      @Override
+      void log(int aLine, String aKey, Object aObject) {
+        CustomRegexpHeaderCheck.this.log(aLine, aKey, aObject);
+      }
+    });
+  }
+
+  /**
+   * Check the current file using the same method as {@link RegexpHeaderCheck#beginTree(DetailAST)}
+   * but pass all logging calls through a custom log handler (@see {@link CustomLogHandler}).
+   * 
+   * @param logHandler the custom log handler, or <code>null</code> to suppress logging.
+   */
+  public void doChecks(CustomLogHandler logHandler) {
+    // With the exception of the logging hooks, the following is copied from
+    // RegexpHeaderCheck.beginTree().
+
+    final int headerSize = getHeaderLines().length;
+    final int fileSize = getLines().length;
+
+    if (headerSize - mMultiLines.length > fileSize) {
+      if (logHandler != null) {
+        logHandler.log(1, "gwtheader.missing", null);
+      }
+    } else {
+      int headerLineNo = 0;
+      int i;
+      for (i = 0; (headerLineNo < headerSize) && (i < fileSize); i++) {
+        boolean isMatch = isMatch(i, headerLineNo);
+        while (!isMatch && isMultiLine(headerLineNo)) {
+          headerLineNo++;
+          isMatch = (headerLineNo == headerSize) || isMatch(i, headerLineNo);
+        }
+        if (!isMatch) {
+          if (logHandler != null) {
+            logHandler.log(i + 1, "gwtheader.mismatch", getHeaderLines()[headerLineNo]);
+          }
+          break; // stop checking
+        }
+        if (!isMultiLine(headerLineNo)) {
+          headerLineNo++;
+        }
+      }
+      if (i == fileSize) {
+        // if file finished, but we have at least one non-multi-line
+        // header isn't completed
+        for (; headerLineNo < headerSize; headerLineNo++) {
+          if (!isMultiLine(headerLineNo)) {
+            if (logHandler != null) {
+              logHandler.log(1, "gwtheader.missing");
+            }
+            break;
+          }
+        }
+      }
+    }
+  }
+
+  /**
+   * {@inheritDoc}
+   */
+  @Override
+  public void setHeader(String aHeader) {
+    super.setHeader(aHeader);
+    initHeaderRegexps();
+  }
+
+  /**
+   * {@inheritDoc}
+   */
+  @Override
+  public void setHeaderFile(String aFileName) throws ConversionException {
+    super.setHeaderFile(aFileName);
+    initHeaderRegexps();
+  }
+
+  /**
+   * {@inheritDoc}
+   */
+  @Override
+  public void setMultiLines(int[] aList) {
+    if ((aList == null) || (aList.length == 0)) {
+      mMultiLines = EMPTY_INT_ARRAY;
+      return;
+    }
+
+    mMultiLines = new int[aList.length];
+    System.arraycopy(aList, 0, mMultiLines, 0, aList.length);
+    Arrays.sort(mMultiLines);
+  }
+
+  /**
+   * Initializes {@link #mHeaderRegexps} from {@link AbstractHeaderCheck#getHeaderLines()}.
+   */
+  private void initHeaderRegexps() {
+    final String[] headerLines = getHeaderLines();
+    if (headerLines != null) {
+      mHeaderRegexps = new Pattern[headerLines.length];
+      for (int i = 0; i < headerLines.length; i++) {
+        try {
+          // todo: Not sure if chache in Utils is still necessary
+          mHeaderRegexps[i] = Utils.getPattern(headerLines[i]);
+        } catch (final PatternSyntaxException ex) {
+          throw new ConversionException("line " + i + " in header specification"
+              + " is not a regular expression");
+        }
+      }
+    }
+  }
+
+  /**
+   * Checks if a code line matches the required header line.
+   * 
+   * @param aLineNo the line number to check against the header
+   * @param aHeaderLineNo the header line number.
+   * @return true if and only if the line matches the required header line.
+   */
+  private boolean isMatch(int aLineNo, int aHeaderLineNo) {
+    final String line = getLines()[aLineNo];
+    return mHeaderRegexps[aHeaderLineNo].matcher(line).find();
+  }
+
+  /**
+   * @param aLineNo a line number
+   * @return if <code>aLineNo</code> is one of the repeat header lines.
+   */
+  private boolean isMultiLine(int aLineNo) {
+    return (Arrays.binarySearch(mMultiLines, aLineNo + 1) >= 0);
+  }
+}
\ No newline at end of file
diff --git a/build-tools/customchecks/src/com/google/gwt/checkstyle/GwtHeaderCheck.java b/build-tools/customchecks/src/com/google/gwt/checkstyle/GwtHeaderCheck.java
new file mode 100644
index 0000000..0457136
--- /dev/null
+++ b/build-tools/customchecks/src/com/google/gwt/checkstyle/GwtHeaderCheck.java
@@ -0,0 +1,89 @@
+/*
+ * Copyright 2011 Google Inc.
+ * 
+ * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except
+ * in compliance with the License. You may obtain a copy of the License at
+ * 
+ * http://www.apache.org/licenses/LICENSE-2.0
+ * 
+ * Unless required by applicable law or agreed to in writing, software distributed under the License
+ * is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express
+ * or implied. See the License for the specific language governing permissions and limitations under
+ * the License.
+ */
+
+package com.google.gwt.checkstyle;
+
+import com.google.gwt.checkstyle.CustomRegexpHeaderCheck.CustomLogHandler;
+
+import com.puppycrawl.tools.checkstyle.api.Check;
+import com.puppycrawl.tools.checkstyle.api.DetailAST;
+
+/**
+ * Checks the header against one of two header options, to support GWT's 80 and 100 column headers.
+ * <p>
+ * To use, set <code>&lt;property name="header" value="[regular expression]" /&gt;</code> and
+ * <code>&lt;property name="headerAlt" value="[alternate regular expression]" /&gt;</code>
+ */
+public class GwtHeaderCheck extends Check {
+  private CustomRegexpHeaderCheck regexpChecker = new CustomRegexpHeaderCheck();
+  private CustomRegexpHeaderCheck regexpCheckerAlt = new CustomRegexpHeaderCheck();
+
+  public void beginTree(DetailAST aRootAST) {
+    final boolean[] passedChecks = new boolean[]{true};
+    regexpChecker.setFileContents(this.getFileContents());
+    regexpChecker.doChecks(new CustomLogHandler() {
+      @Override
+      void log(int aLine, String aKey) {
+        passedChecks[0] = false;
+      }
+
+      @Override
+      void log(int aLine, String aKey, Object aObject) {
+        passedChecks[0] = false;
+      }
+    });
+    if (passedChecks[0]) {
+      // regexpChecker passed, no need to run alternate checker
+      return;
+    }
+
+    regexpCheckerAlt.setFileContents(this.getFileContents());
+    regexpCheckerAlt.doChecks(new CustomLogHandler() {
+      @Override
+      void log(int aLine, String aKey) {
+        GwtHeaderCheck.this.log(aLine, aKey);
+      }
+
+      @Override
+      void log(int aLine, String aKey, Object aObject) {
+        GwtHeaderCheck.this.log(aLine, aKey, aObject);
+      }
+    });
+  }
+
+  @Override
+  public int[] getDefaultTokens() {
+    return new int[0];
+  }
+
+  /**
+   * Set the header to check against. Individual lines in the header must be separated by '\n'
+   * characters.
+   * 
+   * @param aHeader header content to check against.
+   */
+  public void setHeader(String aHeader) {
+    regexpChecker.setHeader(aHeader);
+  }
+
+  /**
+   * Set the alternate header to check against. Individual lines in the header must be separated by
+   * '\n' characters.
+   * 
+   * @param aHeader header content to check against.
+   */
+  public void setHeaderAlt(String aHeader) {
+    regexpCheckerAlt.setHeader(aHeader);
+  }
+}
\ No newline at end of file
diff --git a/build-tools/customchecks/src/com/google/gwt/checkstyle/messages.properties b/build-tools/customchecks/src/com/google/gwt/checkstyle/messages.properties
new file mode 100644
index 0000000..149391c
--- /dev/null
+++ b/build-tools/customchecks/src/com/google/gwt/checkstyle/messages.properties
@@ -0,0 +1,2 @@
+gwtheader.missing=Missing a header - not enough lines in file.
+gwtheader.mismatch=Line does not match expected header line of ''{0}''.
\ No newline at end of file
diff --git a/eclipse/settings/code-style/gwt-checkstyle-tests.xml b/eclipse/settings/code-style/gwt-checkstyle-tests.xml
index 34ad279..d27c8e2 100644
--- a/eclipse/settings/code-style/gwt-checkstyle-tests.xml
+++ b/eclipse/settings/code-style/gwt-checkstyle-tests.xml
@@ -87,10 +87,11 @@
             <property name="logLoadErrors" value="true"/>
             <property name="tokens" value="METHOD_DEF"/>
         </module>
-        <module name="RegexpHeader">
-            <property name="severity" value="error"/>
-            <property name="header" value="/\*\n \* Copyright 20(0[6789]|[12][0-9]) Google Inc\.\n \*[ ]*\n \* Licensed under the Apache License, Version 2\.0 \(the &quot;License&quot;\); you may not\n \* use this file except in compliance with the License\. You may obtain a copy of\n \* the License at\n \*[ ]*\n \* http://www\.apache\.org/licenses/LICENSE-2\.0\n \*[ ]*\n \* Unless required by applicable law or agreed to in writing, software\n \* distributed under the License is distributed on an &quot;AS IS&quot; BASIS, WITHOUT\n \* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied\. See the\n \* License for the specific language governing permissions and limitations under\n \* the License\.\n \*/"/>
-        </module>
+        <module name="com.google.gwt.checkstyle.GwtHeaderCheck">
+           <property name="severity" value="error"/>
+           <property name="header" value="/\*\n \* Copyright 20(0[6789]|[12][0-9]) Google Inc\.\n \*[ ]*\n \* Licensed under the Apache License, Version 2\.0 \(the &quot;License&quot;\); you may not\n \* use this file except in compliance with the License\. You may obtain a copy of\n \* the License at\n \*[ ]*\n \* http://www\.apache\.org/licenses/LICENSE-2\.0\n \*[ ]*\n \* Unless required by applicable law or agreed to in writing, software\n \* distributed under the License is distributed on an &quot;AS IS&quot; BASIS, WITHOUT\n \* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied\. See the\n \* License for the specific language governing permissions and limitations under\n \* the License\.\n \*/"/>
+           <property name="headerAlt" value="/\*\n \* Copyright 20(0[6789]|[12][0-9]) Google Inc\.\n \*[ ]*\n \* Licensed under the Apache License, Version 2\.0 \(the &quot;License&quot;\); you may not use this file except\n \* in compliance with the License\. You may obtain a copy of the License at\n \*[ ]*\n \* http://www\.apache\.org/licenses/LICENSE-2\.0\n \*[ ]*\n \* Unless required by applicable law or agreed to in writing, software distributed under the License\n \* is distributed on an &quot;AS IS&quot; BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express\n \* or implied\. See the License for the specific language governing permissions and limitations under\n \* the License\.\n \*/"/>
+       </module>
         <module name="ImportOrder">
             <property name="severity" value="error"/>
             <property name="groups" value="com.google, com,  junit, net,org, java,javax"/>
diff --git a/eclipse/settings/code-style/gwt-checkstyle.xml b/eclipse/settings/code-style/gwt-checkstyle.xml
index 74607bb..c3c30d3 100644
--- a/eclipse/settings/code-style/gwt-checkstyle.xml
+++ b/eclipse/settings/code-style/gwt-checkstyle.xml
@@ -80,10 +80,11 @@
             <property name="logLoadErrors" value="true"/>
             <property name="tokens" value="METHOD_DEF"/>
         </module>
-        <module name="RegexpHeader">
-            <property name="severity" value="error"/>
-            <property name="header" value="/\*\n \* Copyright 20(0[6789]|[12][0-9]) Google Inc\.\n \*[ ]*\n \* Licensed under the Apache License, Version 2\.0 \(the &quot;License&quot;\); you may not\n \* use this file except in compliance with the License\. You may obtain a copy of\n \* the License at\n \*[ ]*\n \* http://www\.apache\.org/licenses/LICENSE-2\.0\n \*[ ]*\n \* Unless required by applicable law or agreed to in writing, software\n \* distributed under the License is distributed on an &quot;AS IS&quot; BASIS, WITHOUT\n \* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied\. See the\n \* License for the specific language governing permissions and limitations under\n \* the License\.\n \*/"/>            
-        </module>
+        <module name="com.google.gwt.checkstyle.GwtHeaderCheck">
+           <property name="severity" value="error"/>
+           <property name="header" value="/\*\n \* Copyright 20(0[6789]|[12][0-9]) Google Inc\.\n \*[ ]*\n \* Licensed under the Apache License, Version 2\.0 \(the &quot;License&quot;\); you may not\n \* use this file except in compliance with the License\. You may obtain a copy of\n \* the License at\n \*[ ]*\n \* http://www\.apache\.org/licenses/LICENSE-2\.0\n \*[ ]*\n \* Unless required by applicable law or agreed to in writing, software\n \* distributed under the License is distributed on an &quot;AS IS&quot; BASIS, WITHOUT\n \* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied\. See the\n \* License for the specific language governing permissions and limitations under\n \* the License\.\n \*/"/>
+           <property name="headerAlt" value="/\*\n \* Copyright 20(0[6789]|[12][0-9]) Google Inc\.\n \*[ ]*\n \* Licensed under the Apache License, Version 2\.0 \(the &quot;License&quot;\); you may not use this file except\n \* in compliance with the License\. You may obtain a copy of the License at\n \*[ ]*\n \* http://www\.apache\.org/licenses/LICENSE-2\.0\n \*[ ]*\n \* Unless required by applicable law or agreed to in writing, software distributed under the License\n \* is distributed on an &quot;AS IS&quot; BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express\n \* or implied\. See the License for the specific language governing permissions and limitations under\n \* the License\.\n \*/"/>
+       </module>
         <module name="ImportOrder">
             <property name="severity" value="error"/>
             <property name="groups" value="com.google, com,  junit, net,org, java,javax"/>
diff --git a/eclipse/settings/code-style/gwt-customchecks.jar b/eclipse/settings/code-style/gwt-customchecks.jar
index b344d4c..1b51aa7 100644
--- a/eclipse/settings/code-style/gwt-customchecks.jar
+++ b/eclipse/settings/code-style/gwt-customchecks.jar
Binary files differ
diff --git a/eclipse/settings/code-style/gwt-format.xml b/eclipse/settings/code-style/gwt-format.xml
index e3b7569..b13daa7 100644
--- a/eclipse/settings/code-style/gwt-format.xml
+++ b/eclipse/settings/code-style/gwt-format.xml
@@ -64,7 +64,7 @@
 <setting id="org.eclipse.jdt.core.formatter.comment.indent_root_tags" value="true"/>
 <setting id="org.eclipse.jdt.core.formatter.comment.insert_new_line_before_root_tags" value="insert"/>
 <setting id="org.eclipse.jdt.core.formatter.comment.insert_new_line_for_parameter" value="do not insert"/>
-<setting id="org.eclipse.jdt.core.formatter.comment.line_length" value="80"/>
+<setting id="org.eclipse.jdt.core.formatter.comment.line_length" value="100"/>
 <setting id="org.eclipse.jdt.core.formatter.comment.new_lines_at_block_boundaries" value="true"/>
 <setting id="org.eclipse.jdt.core.formatter.comment.new_lines_at_javadoc_boundaries" value="true"/>
 <setting id="org.eclipse.jdt.core.formatter.compact_else_if" value="true"/>