Ah yes, on 5.5 the directory is /usr/lib/vmware-vsphere-client/server/repository/ext. Thanks. Now I can compare the two sets of jar files. What is still NOT clear is "Are there other directories with jar files that are in my classpath?"
So, in 5.5 plug-in developers have:
ch.qos.logback.classic_1.0.7.v20121108-1250.jarch.qos.logback.core_1.0.7.v20121108-1250.jarch.qos.logback.slf4j_1.0.7.v20121108-1250.jarcom.springsource.javax.portlet_2.0.0.v20110525.jarcom.springsource.javax.servlet.jsp.jstl_1.2.0.v20110728.jarcom.springsource.org.aopalliance_1.0.0.jarcom.springsource.org.apache.commons.codec_1.3.0.jarcom.springsource.org.apache.commons.fileupload_1.2.0.v20110525.jarcom.springsource.org.apache.commons.httpclient_3.1.0.jarcom.springsource.org.apache.commons.io_1.4.0.jarcom.springsource.org.apache.taglibs.standard_1.1.2.v20110517.jarcom.springsource.org.aspectj.weaver_1.6.12.RELEASE.jarjavax.annotation_1.1.0.v201108011116.jarjavax.ejb_3.1.1.v201204261316.jarjavax.el_2.2.0.v201108011116.jarjavax.jms_1.1.0.v201205091237.jarjavax.mail_1.4.0.v201005080615.jarjavax.persistence_2.0.4.v201112161009.jarjavax.servlet.jsp_2.2.0.v201112011158.jarjavax.servlet_3.0.0.v201112011016.jarjavax.xml.rpc_1.1.0.v201005080400.jarorg.apache.catalina.ha_7.0.35.v201302131607.jarorg.apache.catalina.tribes_7.0.35.v201302140645.jarorg.apache.catalina_7.0.35.v201302131125.jarorg.apache.coyote_7.0.35.v201302140645.jarorg.apache.el_7.0.35.v201302120746.jarorg.apache.jasper_7.0.35.v201302161127.jarorg.apache.juli.extras_7.0.35.v201302120746.jarorg.apache.tomcat.api_7.0.35.v201302120746.jarorg.apache.tomcat.util_7.0.35.v201302140645.jarorg.eclipse.equinox.cm_1.0.400.v20120319-2029.jarorg.eclipse.equinox.ds_1.4.0.v20120112-1400.jarorg.eclipse.equinox.event_1.2.100.v20111010-1614.jarorg.eclipse.equinox.log_1.2.300.v20120522-2049.jarorg.eclipse.equinox.region_1.1.0.v20120319-1602.jarorg.eclipse.equinox.util_1.0.300.v20111010-1614.jarorg.eclipse.gemini.blueprint.core_1.0.2.RELEASE.jarorg.eclipse.gemini.blueprint.extender_1.0.2.RELEASE.jarorg.eclipse.gemini.blueprint.io_1.0.2.RELEASE.jarorg.eclipse.gemini.management_1.0.5.RELEASE.jarorg.eclipse.gemini.web.core_2.2.2.RELEASE.jarorg.eclipse.gemini.web.tomcat_2.2.2.RELEASE.jarorg.eclipse.jdt.core.compiler.batch_3.8.0.I20120518-2145.jarorg.eclipse.osgi.services_3.3.0.v20120307-2102.jarorg.eclipse.virgo.apps.repository.propertiesorg.eclipse.virgo.kernel.agent.dm_3.6.2.RELEASE.jarorg.eclipse.virgo.kernel.artifact_3.6.2.RELEASE.jarorg.eclipse.virgo.kernel.deployer.dm_3.6.2.RELEASE.jarorg.eclipse.virgo.kernel.deployer_3.6.2.RELEASE.jarorg.eclipse.virgo.kernel.dmfragment_3.6.2.RELEASE.jarorg.eclipse.virgo.kernel.equinox.extensions_3.6.2.RELEASE.jarorg.eclipse.virgo.kernel.osgi_3.6.2.RELEASE.jarorg.eclipse.virgo.kernel.services_3.6.2.RELEASE.jarorg.eclipse.virgo.kernel.userregion.blueprint.planorg.eclipse.virgo.kernel.userregion_3.6.2.RELEASE.jarorg.eclipse.virgo.management.fragment_3.6.2.RELEASE.jarorg.eclipse.virgo.management.planorg.eclipse.virgo.medic.core_3.6.2.RELEASE.jarorg.eclipse.virgo.medic_3.6.2.RELEASE.jarorg.eclipse.virgo.nano.core_3.6.2.RELEASE.jarorg.eclipse.virgo.nano.deployer.api_3.6.2.RELEASE.jarorg.eclipse.virgo.nano.deployer.hot_3.6.2.RELEASE.jarorg.eclipse.virgo.repository_3.6.2.RELEASE.jarorg.eclipse.virgo.util.common_3.6.2.RELEASE.jarorg.eclipse.virgo.util.io_3.6.2.RELEASE.jarorg.eclipse.virgo.util.math_3.6.2.RELEASE.jarorg.eclipse.virgo.util.osgi.manifest_3.6.2.RELEASE.jarorg.eclipse.virgo.util.osgi_3.6.2.RELEASE.jarorg.eclipse.virgo.util.parser.manifest_3.6.2.RELEASE.jarorg.eclipse.virgo.web.core_3.6.2.RELEASE.jarorg.eclipse.virgo.web.dm_3.6.2.RELEASE.jarorg.eclipse.virgo.web.propertiesorg.eclipse.virgo.web.servlet.adapter_3.6.2.RELEASE.jarorg.eclipse.virgo.web.spring.integration_3.6.2.RELEASE.jarorg.eclipse.virgo.web.tomcat.support_3.6.2.RELEASE.jarorg.eclipse.virgo.web.tomcat_3.6.2.RELEASE.planorg.jolokia.osgi_1.0.2.jarorg.osgi.enterprise_4.2.0.v201108120515.jarorg.slf4j.api_1.7.2.v20121108-1250.jarorg.slf4j.jcl_1.7.2.v20121108-1250.jarorg.slf4j.jul_1.7.2.v20121108-1250.jarorg.slf4j.log4j_1.7.2.v20130115-1340.jarorg.slf4j.nop_1.7.2.v201212060727.jarorg.springframework.spring-library_3.1.2.RELEASE.libdosgi.console.propertiesspring-aop-3.1.2.RELEASE.jarspring-asm-3.1.2.RELEASE.jarspring-aspects-3.1.2.RELEASE.jarspring-beans-3.1.2.RELEASE.jarspring-context-3.1.2.RELEASE.jarspring-context-support-3.1.2.RELEASE.jarspring-core-3.1.2.RELEASE.jarspring-expression-3.1.2.RELEASE.jarspring-jdbc-3.1.2.RELEASE.jarspring-jms-3.1.2.RELEASE.jarspring-orm-3.1.2.RELEASE.jarspring-oxm-3.1.2.RELEASE.jarspring-tx-3.1.2.RELEASE.jarspring-web-3.1.2.RELEASE.jarspring-webmvc-3.1.2.RELEASE.jarspring-webmvc-portlet-3.1.2.RELEASE.jar
and in 6.0 developers have:
afdClient-6.0.0.jaramfext-6.0.0.jarblazeds-common-4.0.1.21287.p1.jarblazeds-core-4.0.1.21287.p1.jarblazeds-proxy-4.0.1.21287.p1.jarblazeds-remoting-4.0.1.21287.p1.jarcisCommon-6.0.0.jarcisKvVmodl-6.0.0.jarcm-client-6.0.0.jarcm-service-6.0.0.jarcmCommon-6.0.0.jarcmVmodl-6.0.0.jarcom.springsource.edu.oswego.cs.dl.util.concurrent-1.3.4.jarcom.springsource.net.jcip.annotations-1.0.0.jarcom.springsource.net.sf.cglib-2.1.3.jarcom.springsource.org.apache.bcel-5.1.0.jarcom.springsource.org.apache.commons.beanutils-1.7.0.jarcom.springsource.org.apache.commons.codec-1.4.0.jarcom.springsource.org.apache.commons.collections-3.2.1.jarcom.springsource.org.apache.commons.configuration-1.5.0.jarcom.springsource.org.apache.commons.digester-1.8.0.jarcom.springsource.org.apache.commons.httpclient-3.1.0.jarcom.springsource.org.apache.commons.jxpath-1.2.0.jarcom.springsource.org.apache.commons.lang-2.5.0.jarcom.springsource.org.apache.commons.logging-1.1.1.jarcom.springsource.org.apache.commons.pool-1.5.3.jarcom.springsource.org.apache.log4j-1.2.15.jarcom.springsource.org.apache.regexp-1.5.0.jarcom.springsource.org.apache.xalan-2.7.0.jarcom.springsource.org.apache.xerces-2.8.1.jarcom.springsource.org.apache.xml.resolver-1.2.0.jarcom.springsource.org.apache.xml.security-1.4.2.jarcom.springsource.org.apache.xmlcommons-1.3.3.jarcom.springsource.org.bouncycastle.jce-1.39.0.jarcom.springsource.org.jdom-1.0.0.jarcom.springsource.org.jgroups-2.5.1.jarcom.springsource.org.joda.time-1.6.0.jarcommons-codec-1.6.jarcommons-compress-1.8.jarcommons-exec-1.1.jarcommons-io-2.4.jarcr-6.0.0.jardata-service-adapters-6.0.0.jardata-services-6.0.0.jardataserviceVmodl-6.0.0.jardisruptor-3.2.1.jardsVmodl-6.0.0.jarehcache-core-2.6.2.jaresapi-2.0.1.jarextension-framework-server-6.0.0.jarfscr-6.0.0.jargs-collections-5.1.0.jargs-collections-api-5.1.0.jarguava-15.0.jarhelp-service-6.0.0.jarhttpSsoAuth-6.0.0.jarhttpasyncclient-osgi-4.0.1.jarhttpclient-cache-4.3.2.jarhttpclient-osgi-4.3.3.jarhttpcore-nio-4.3.2.jarhttpcore-osgi-4.3.2.jarhttpmime-4.3.2.jarini4j-0.5.2.jarjackson-annotations-2.4.1.jarjackson-core-2.4.1.jarjackson-core-asl-1.9.6.jarjackson-databind-2.4.1.jarjackson-jaxrs-1.9.6.jarjackson-mapper-asl-1.9.6.jarjackson-module-afterburner-2.4.1.jarjamon-2.4.jarjasperreports-4.0.1.jarjava-model-core-6.0.0.jarjava-util-6.0.0.jarjavax.servlet-api-3.0.1.jarjson-path-0.9.1.jarjson-simple-1.1.1.jarjson-smart-1.2.jarjsr305-2.0.1.jarjsr311-api-1.1.1.jarkryo-2.24.0.jarlicense-cis-vmodl-bindings-6.0.0.jarlicense-client-6.0.0.jarlicense-common-6.0.0.jarlicenseVmodl-6.0.0.jarlocalKvVmodl-6.0.0.jarlog4j-over-slf4j-1.6.1.jarlookupVmodl-6.0.0.jarminlog-1.2.jarmixed-service-6.0.0.jarnot-yet-commons-ssl-0.3.9.jarobjenesis-2.1.jarorg.apache.servicemix.bundles.opensaml-2.5.1_1.jarorg.springframework.aop-3.1.4.RELEASE.jarorg.springframework.asm-3.1.4.RELEASE.jarorg.springframework.aspects-3.1.4.RELEASE.jarorg.springframework.beans-3.1.4.RELEASE.jarorg.springframework.context-3.1.4.RELEASE.jarorg.springframework.context.support-3.1.4.RELEASE.jarorg.springframework.core-3.1.4.RELEASE.jarorg.springframework.expression-3.1.4.RELEASE.jarorg.springframework.jdbc-3.1.4.RELEASE.jarorg.springframework.jms-3.1.4.RELEASE.jarorg.springframework.orm-3.1.4.RELEASE.jarorg.springframework.oxm-3.1.4.RELEASE.jarorg.springframework.transaction-3.1.4.RELEASE.jarorg.springframework.web-3.1.4.RELEASE.jarorg.springframework.web.portlet-3.1.4.RELEASE.jarorg.springframework.web.servlet-3.1.4.RELEASE.jarpbmVmodl-6.0.0.jarpersistence-framework-server-6.0.0.jarph-client-all-6.0.0.jarprotobuf-java-2.5.0.jarqueryClient-6.0.0.jarqueryCore-6.0.0.jarqueryVmodl-6.0.0.jarreactor-core-1.1.2.RELEASE.jarreactor-spring-1.0.1.RELEASE.jarreflectVmodl-6.0.0.jarreporting-service-6.0.0.jarscaVmodl-6.0.0.jarsearch-6.0.0.jarsecurity-framework-server-6.0.0.jarsecurity-service-6.0.0.jarsecurity-service-vsphere-6.0.0.jarserver-common-6.0.0.jarserviceCommon-6.0.0.jarslf4j-api-1.6.1.jarsmsVmodl-6.0.0.jarsnappy-java-1.1.1.3.jarspring-flex-core-1.5.2.RELEASE.jarspring-security-config-3.1.4.RELEASE.jarspring-security-core-3.1.4.RELEASE.jarspring-security-web-3.1.4.RELEASE.jarspsVmodl-6.0.0.jarssoClient-6.0.0.jarssoVmodl-6.0.0.jarstax-api-1.0.1.jarstax2-api-3.0.1.jarstretchedvsan-vmodl.jarvapi-cis-resourcebundle-6.0.0.jarvapiAuthn-6.0.0.jarvapiCisInventoryService-6.0.0.jarvapiCommon-6.0.0.jarvapiCommonClient-6.0.0.jarvapiInventoryService-6.0.0.jarvapiRuntime-6.0.0.jarvelocity-1.7.jarvim-commons-6.0.0.jarvim-commons-vsphere-6.0.0.jarvim-messaging-websocket-6.0.0.jarvim-services-6.0.0.jarvim-services-vsphere-6.0.0.jarvimVmodl-6.0.0.jarvlsiClient-6.0.0.jarvlsiCore-6.0.0.jarvlsiServer-6.0.0.jarvmcaClient-6.0.0.jarvmodl2-authz-6.0.0.jarvmodl2-ds-6.0.0.jarvmodl2-vapi-endpoint-6.0.0.jarvmodlCommon-6.0.0.jarvsan-vmodl-6.0.0-3179137-javadoc.jarvsan-vmodl-6.0.0-3179137.jarwebssoClient-6.0.0.jarwoodstox-core-asl-4.0.5.jarws-commons-util-1.0.2.jarxmlrpc-client-3.1.3.jarxmlrpc-common-3.1.3.jar