http://xml.apache.org/commons/components/external/: xml-commons provides an Apache-hosted set of DOM, SAX, and JAXP interfaces for use in other xml-based projects. Our hope is that we can standardize on both a common version and packaging scheme for these critical XML standards interfaces to make the lives of both our developers and users easier. The External Components portion of xml-commons contains interfaces that are defined by external standards organizations. For DOM, that's the W3C; for SAX it's David Megginson and sax.sourceforge.net; for JAXP it's Sun. 
public class org.apache.xmlcommons.Version
  minor version: 0
  major version: 59
  flags: flags: (0x0021) ACC_PUBLIC, ACC_SUPER
  this_class: org.apache.xmlcommons.Version
  super_class: java.lang.Object
{
  public void <init>();
    descriptor: ()V
    flags: (0x0001) ACC_PUBLIC
    Code:
      stack=1, locals=1, args_size=1
        start local 0 // org.apache.xmlcommons.Version this
         0: .line 26
            aload 0 /* this */
            invokespecial java.lang.Object.<init>:()V
            return
        end local 0 // org.apache.xmlcommons.Version this
      LocalVariableTable:
        Start  End  Slot  Name  Signature
            0    1     0  this  Lorg/apache/xmlcommons/Version;

  public static java.lang.String getVersion();
    descriptor: ()Ljava/lang/String;
    flags: (0x0009) ACC_PUBLIC, ACC_STATIC
    Code:
      stack=3, locals=0, args_size=0
         0: .line 41
            new java.lang.StringBuilder
            dup
            invokestatic org.apache.xmlcommons.Version.getProduct:()Ljava/lang/String;
            invokestatic java.lang.String.valueOf:(Ljava/lang/Object;)Ljava/lang/String;
            invokespecial java.lang.StringBuilder.<init>:(Ljava/lang/String;)V
            ldc " "
            invokevirtual java.lang.StringBuilder.append:(Ljava/lang/String;)Ljava/lang/StringBuilder;
            invokestatic org.apache.xmlcommons.Version.getVersionNum:()Ljava/lang/String;
            invokevirtual java.lang.StringBuilder.append:(Ljava/lang/String;)Ljava/lang/StringBuilder;
            invokevirtual java.lang.StringBuilder.toString:()Ljava/lang/String;
            areturn
      LocalVariableTable:
        Start  End  Slot  Name  Signature

  public static java.lang.String getProduct();
    descriptor: ()Ljava/lang/String;
    flags: (0x0009) ACC_PUBLIC, ACC_STATIC
    Code:
      stack=1, locals=0, args_size=0
         0: .line 51
            ldc "XmlCommonsExternal"
            areturn
      LocalVariableTable:
        Start  End  Slot  Name  Signature

  public static java.lang.String getVersionNum();
    descriptor: ()Ljava/lang/String;
    flags: (0x0009) ACC_PUBLIC, ACC_STATIC
    Code:
      stack=1, locals=0, args_size=0
         0: .line 60
            ldc "1.4.01"
            areturn
      LocalVariableTable:
        Start  End  Slot  Name  Signature

  public static void main(java.lang.String[]);
    descriptor: ([Ljava/lang/String;)V
    flags: (0x0009) ACC_PUBLIC, ACC_STATIC
    Code:
      stack=2, locals=1, args_size=1
        start local 0 // java.lang.String[] argv
         0: .line 69
            getstatic java.lang.System.out:Ljava/io/PrintStream;
            invokestatic org.apache.xmlcommons.Version.getVersion:()Ljava/lang/String;
            invokevirtual java.io.PrintStream.println:(Ljava/lang/String;)V
         1: .line 70
            return
        end local 0 // java.lang.String[] argv
      LocalVariableTable:
        Start  End  Slot  Name  Signature
            0    2     0  argv  [Ljava/lang/String;
    MethodParameters:
      Name  Flags
      argv  
}
SourceFile: "Version.java"