To get the list of services in HTML format use listHTML() method:

@GET
@Produces({MediaType.TEXT_HTML})
public byte[] listHTML()
{
   ...
}  

To do this, perform a simple GET request to the RestServicesList link.

f.e. curl -u root:exo http://localhost:8080/rest/ will return such HTML code:

<?xml version="1.0" encoding="UTF-8"?><!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
   <head>
      <title>eXo JAXRS Implementation</title>
   </head>
   <body>
      <h3 style="text-align:center;">Root resources</h3>
      <table   width="90%"   style="table-layout:fixed;">
         <tr>
            <th>Path</th>
            <th>Regex</th>
            <th>FQN</th>
         </tr>
         <tr>
            <td>script/groovy</td>
            <td>/script/groovy(/.*)?</td>
            <td>org.exoplatform.services.jcr.ext.script.groovy.GroovyScript2RestLoader</td>
         </tr>
         <tr>
            <td>/lnkproducer/</td>
            <td>/lnkproducer(/.*)?</td>
            <td>org.exoplatform.services.jcr.webdav.lnkproducer.LnkProducer</td>
         </tr>
         <tr>
            <td>/registry/</td>
            <td>/registry(/.*)?</td>
            <td>org.exoplatform.services.jcr.ext.registry.RESTRegistryService</td>
         </tr>
         <tr>
            <td>/jcr</td>
            <td>/jcr(/.*)?</td>
            <td>org.exoplatform.services.jcr.webdav.WebDavServiceImpl</td>
         </tr>
         <tr>
            <td>/</td>
            <td>(/.*)?</td>
            <td>org.exoplatform.services.rest.ext.service.RestServicesList</td>
         </tr>
      </table>
   </body>
</html>    

If you perform the same request with your browser, you'll see the table with the list of deployed services like this: