This is before. With JRiver 15 on Windows, the only bad thing it did was add "TOOL Name" and "TOOL Version". But it would not molest the other tags:
comment[0]: AccurateRipResult=AccurateRip: Accurate (confidence 9) [BD1EFF36]
comment[1]: AccurateRipDiscID=010-00101495-007fe260-a00a3d0a-1
comment[2]: CRC=D501AA42
comment[3]: Composer=Billy Joel
comment[4]: UPC=821797206266
comment[5]: Artist=Billy Joel
comment[6]: Title=Travelin' Prayer
comment[7]: Album=Piano Man (MFSL)
comment[8]: Genre=Pop
comment[9]: Date=1973
comment[10]: TRACKNUMBER=1
comment[11]: CDTOC=A+96+4BDB+AF29+E96E+1221B+18800+1C132+2060C+244C5+27F51+30090
comment[12]: CDDB Disc ID=A00A3D0A
comment[13]: Remastered=MFSL
comment[14]: RemasteredDate=2010
comment[15]: TOOL NAME=Media Center
comment[16]: TOOL VERSION=15.0.80
Now with JRiver on Linux it feels it needs to re-order and capitalise other tags:
comment[0]: AccurateRipResult=AccurateRip: Accurate (confidence 9) [BD1EFF36]
comment[1]: AccurateRipDiscID=010-00101495-007fe260-a00a3d0a-1
comment[2]: CRC=D501AA42
comment[3]: CDTOC=A+96+4BDB+AF29+E96E+1221B+18800+1C132+2060C+244C5+27F51+30090
comment[4]: CDDB Disc ID=A00A3D0A
comment[5]: Remastered=MFSL
comment[6]: RemasteredDate=2010
comment[7]: TOOL NAME=Media Center
comment[8]: TRACKNUMBER=1
comment[9]: DATE=1973
comment[10]: GENRE=Pop
comment[11]: ALBUM=Piano Man (MFSL)
comment[12]: TITLE=Travelin' Prayerx
comment[13]: ARTIST=Billy Joel
comment[14]: UPC=821797206266
comment[15]: COMPOSER=Billy Joel