Application specific layers

Is there a method for creating your own layer of information, either as an open “instance” of stuff such as tourist routes (openlayers is this slippy map stuff right ?), or as a private/corporate layer, e.g. where all our stuff is, etc.

I’d like to run my own OSM compliant instance, with a modified set of objects, using OSM proper as the underlay (would ultimately be nice to tie routes to objects so if the road changes so does the route).
This is obviously a massive issue, there are endless applications. Is there any discussion about this kind of stuff and how one might achieve this.

OpenLayers is the client side of things. The provider of the custom layer(s) is -in the case of OSM mostly- Mapnik.

Perhaps something like these examples:
Show primary highways from OSM and borders and sea levels coming from another source (could be as well your private data),borders,osm_viivat&TRANSPARENT=TRUE&FORMAT=image/png&BBOX=-369151.98300283286,6597900.0,1511076.628895184,8057331.444759207&SRS=EPSG:3067&STYLES=&sql=%28tags%20@%3E%20%27highway=%3Eprimary%27%29

It is a live service and you can select to show secondary highways instead,borders,osm_viivat&TRANSPARENT=TRUE&FORMAT=image/png&BBOX=-369151.98300283286,6597900.0,1511076.628895184,8057331.444759207&SRS=EPSG:3067&STYLES=&sql=%28tags%20@%3E%20%27highway=%3Esecondary%27%29

It is a live service and you can select to show primary but only if they do not have maxspeed tag,borders,osm_viivat&TRANSPARENT=TRUE&FORMAT=image/png&BBOX=-369151.98300283286,6597900.0,1511076.628895184,8057331.444759207&SRS=EPSG:3067&STYLES=&sql=%28tags%20@%3E%20%27highway=%3Eprimary%27%29%20AND%20not%20%28tags%20?%20%27maxspeed%27%29

Do you want to find the hairdresser POIs from OSM? It could be where your stuff is from your private data as well,borders,osm_pisteet&TRANSPARENT=TRUE&FORMAT=image/png&BBOX=-369151.98300283286,6597900.0,1511076.628895184,8057331.444759207&SRS=EPSG:3067&STYLES=&sql=%28tags%20@%3E%20%27shop=%3Ehairdresser%27%29

No Mapnik, no pre-rendered tiles nor OpenLayers are used for these examples. However, it would be easy to add these dynamic layers into OpenLayers map as WMS layers as described in the OpenLayers documentation

Mapnik looks like a one stop shop
many thanks.

If you had your own features marked with a tag like “mark_lesters_own_feature=yes” you could select and show it from my server as easily as you can now show, let’s say “highway=bus_stop”, and without you or me doing anything for the system.,borders,osm_pisteet&TRANSPARENT=TRUE&FORMAT=image/png&BBOX=-369151.98300283286,6597900.0,1511076.628895184,8057331.444759207&SRS=EPSG:3067&STYLES=&sql=%28tags%20@%3E%20%27highway=%3Ebus_stop%27%29

I am sure that Mapnik could be used as an engine to this kind of flexible services. Unfortunately rendering transparent tiles seems to be the only solution that people consider.