A look at LibreOffice 4.4

crude answer, from a source code perspective:

$ git diff --shortstat HEAD..origin/aoo/trunk
94934 files changed, 5510793 insertions(+), 4302273 deletions(-)

Since 2014-01-01
lo:
27877 commits
45435 files changed, 1369710 insertions(+), 1823462 deletions(-)

aoo:
604 commits
4146 files changed, 95774 insertions(+), 66329 deletions(-)

Since 2015-01-01
lo:
2273 commits
14748 files changed, 62035 insertions(+), 87072 deletions(-)

aoo:
43 commits
73 files changed, 1838 insertions(+), 2137 deletions(-)