An example of how to implement looping in a ColdFusion custom tag (http://bit.ly/T5ikmR)

doLoop.cfm

<!--- doLoop.cfm --->
<cf_loop iterations="10" index="i">
    <cfoutput>[#i#]</cfoutput>Hello World<br />
</cf_loop>

loop.cfm

<!--- loop.cfm --->
<cfif (THISTAG.ExecutionMode EQ "Start")>
    <cfparam name="attributes.index" type="variablename">
    <cfparam name="attributes.iterations" type="integer">

    <cfset variables.index = 1>
    <cfset caller[attributes.index] = variables.index>
<cfelse>
    <cfset variables.index = variables.index + 1>
    <cfif variables.index gt attributes.iterations>
        <cfexit method="exittag">
    <cfelse>
        <cfset caller[attributes.index] = variables.index>
        <cfexit method="loop">
    </cfif>
</cfif>