Running xPages in a R7/R8.0 environment

" R8.5 and xPages ante portas!" Not before long and R8.5 will be released and you can deploy the shiny new Domino web2.0 application that created so much buzz. However you can make a safe bet, that your infrastructure team will stop you short: " Not so fast young man, we are not ready". Luckily you don't need to wait for a wholesale upgrade of the entire Domino infrastructure. You just need to add one R8.5 server:

There are a few pointers you need to be aware of:

• The R8.5 server must use the R8.5 templates for all system databases, most notably the Domino directory. R6.5x and R7.0x server work with the 8.5 system templates. If upgrading the system templates is a problem (a real or perceived one) for the infrastructure team, configure replication not to update the design from/to the R8.5 server (you do that by changing the ACLs).
• You need Domino Designer 8.5 for xPage applications. You can use Domino Designer 8.5 to design applications for R6.5/R7.0/R8.0. You just need to test them with the respective client (VMWare and friends are your friend. Or if you got a collection of PCs, use Synergy)
• You must use the Domino Administrator 8.5 to administrate a R8.5 server. You can easily administrate R6.5/R7.0/R8.0 servers using Domino Administrator 8.5
• xPages design elements don't need to be stored in the same NSF as the data. This means that you can design your web application without touching the original NSF design.
• The data sources for xPages can be on a different server. This means you don't even need to replicate your existing databases to your new R8.5 server. However you do want a fast network connection between the two servers. For the R6.5x or R7.x server the xPages application is just another set of users coming in. Of course best performance means local access using ODS48
• Never ever use a lower ODS than you can. ODS stands for On Disk Structure. Domino servers support older version of the ODS. You can use a R5 or R6/7 ODS on an R8 server. But it is not a good idea. The support is meant for the upgrade phase. You upgrade your server, the database then have the old ODS. You run compact and you are good to go (or my favorite: create a new replica). The ODS has no influence on replication. The only catch: you cant FTP a database back on a lower version of the server. This never should be an issue since skilled Domino developers don't FTP, they replicate.