Created attachment 149221 [details]
this enhancement is more or less http://mvnvm.org/ done right, in the IDE.
Based on <prerequisite> element or maven enforcer plugin configuration, try to guess the right version of maven binaries to use.
For prerequisites: use the version matching the pom
for enforcer plugin: when explicit ranges used, try find the highest known matching, otherwise exact match.
Once exact version is determined and not among known runtimes, attempt a download.
The attached patch includes the mechanism to choose and download the binaries and also UI in Tools/Options that enables the feature.
Please note that some related issues where users ask for maven per project could be solved by this, however it must be stated that he $M2_HOME/conf/settings.xml file is still the same within the IDE itself and might contribute to eventual mismatch between the IDE and the cmdline.
fixed in core-main #3982e7d9a166
Integrated into 'main-silver', will be available in build *201410140001* on http://bits.netbeans.org/dev/nightly/ (upload may still be in progress)
User: Tomas Stupka <email@example.com>
Log: Issue #247128 - use pom content to determine what maven binaries to use, download if necessary