Get Multiple list Data using ECMA in a Single Hit.

function GetRegisteredSoft() {

    // debugger;

    clientContext = new SP.ClientContext.get_current();

    var camlQuery = SP.CamlQuery.createAllItemsQuery();

    $.each(list, function (index, lstName) {

        // debugger;

        var oList = clientContext.get_web().get_lists().getByTitle(lstName);

        $("body").data(lstName, oList.getItems(camlQuery));

        clientContext.load($("body").data(lstName));

    });

    clientContext.executeQueryAsync(

       Function.createDelegate(this, this.retrieveSoftwareInfoListItemsSuccess),

       Function.createDelegate(this, this.retrieveSoftwareInfoListItemsFail));

}

function retrieveSoftwareInfoListItemsSuccess() {

    //debugger;

    $.each(list, function (index, lstName) {

        //debugger;

        var result = $("body").data(lstName);

        var empBasicInfoListItemEnumerator = result.getEnumerator();

        while (empBasicInfoListItemEnumerator.moveNext()) {

            var oListItem = empBasicInfoListItemEnumerator.get_current();

            var olistItemSoftware = oListItem.get_item('SoftwareName');

            //alert(olistItemSoftware);

            if (olistItemSoftware != null) {

                availableTags.push(oListItem.get_item('SoftwareName'));

            }

        }

    });

    for (var i = 0; i < availableTags.length; i++) {

        option += '<option value="' + availableTags[i] + '">' + availableTags[i] + '</option>';

    }

    option += '<option value="Other">Other</option>';

    $('#ddlSoftReq').append(option);

}