Delta Developer

Average Rating:6.77
Bayesian Rating:7.26

Total Votes:362

Summary

No description available

Graphs

Rating Distribution

Release Year

Length

Age Rating

Tags (246 total)

NameNovelsAvg ScoreWeight
Animals52.676.33
Dogs62.495.99
Consensual Sex with Animals32.005.91
Pigs41.585.81
Bestiality92.445.73
Sexual Slavery72.754.92
Prostitute Training Simulator13.004.57
Heroine with Gothic Look23.004.28
Birthrate Decline13.003.87
Sexual Devices42.003.83
High Amounts of Rape42.693.80
Gang Rape52.153.68
Insemination by Non-Humanoids22.503.62
Rape72.333.50
Futanari Heroine22.413.47
Urination Fetish51.403.47
Butler Support Character13.003.41
Sex in Front of an Audience42.253.39
Sadist Protagonist13.003.35
Early Sexual Content62.393.35
Foolish Protagonist13.003.30
Futanari Protagonist13.003.27
Voiced Thoughts22.003.25
Mahou Shoujo Protagonist13.003.25
Giant Spider12.003.23
Western-style Manor22.503.23
Royal Protagonist12.603.22
Royal Heroine12.573.22
Human Childbirth12.003.21
Villainous Protagonist22.503.20
Monster Rape22.343.18
Petplay32.003.17
Mindbreak31.673.17
Discreet Masturbation21.503.16
Sex in Public Places82.063.12
Stockings22.003.09
Bondage81.903.09
Loli Protagonist13.003.07
Autofellatio12.003.07
Maid Support Character13.003.06
High Sexual Content72.463.06
Other Perspectives71.983.06
Horse12.003.06
Sex with Insects12.573.04
Wooden Horse21.503.02
Enema31.673.00
Timid Heroine13.003.00
Suction on Penis12.003.00
Huge Insertion22.002.98
Unavoidable Heroine Rape22.002.96
BDSM22.502.96
Multiple Penetration51.802.95
Confinement22.382.94
Sex Involving Drugs22.002.93
Teacher Protagonist22.162.92
Unavoidable Protagonist Rape13.002.89
Futanari on Female21.502.86
Ahegao42.212.85
Exhibitionism41.132.82
Macrophilia12.002.79
Gynecologist Chair12.002.78
Group Sex of Several Females13.002.77
Public Masturbation31.002.76
Heroine with Small Breasts (Non-Loli)22.002.75
Male on Futanari12.002.74
Inflation21.882.74
Arrogant Heroine13.002.73
Heroine with Zettai Ryouiki32.002.71
Leather Bondage12.002.69
Only Bad Endings13.002.68
Clothing Damage21.752.67
Group Sex of One Female and Several Males71.552.65
Outdoor Sex62.202.64
Wedding31.002.63
Tentacle Rape31.952.63
Loli Heroine32.672.62
Sexual Slavery (Choukyou Variation)13.002.61
Student Council12.002.59
Unavoidable Rape13.002.58
Anal Penetration32.002.58
Netori22.002.57
Twin Tail Heroine32.502.52
Straight Shotacon13.002.51
Masturbation41.092.51
Albino Heroine12.002.51
Bukkake41.752.50
Central Heroine13.002.50
Doggy Style102.032.46
Long Sexual Scenes12.672.46
Guro12.002.45
Protagonist's Blood-related Sister as a Heroine12.502.44
Blowbang12.002.44
Netorare31.332.43
Dirty Talk12.002.41
Pornography11.502.40
Musician Heroine12.002.40
Built-in Encyclopedia12.502.36
Revenge13.002.36
Big Breast Sizes Heroine22.502.36
Object Insertion31.002.35
Hidden Vibrator21.502.35
Double Penetration (Group Sex)22.002.34
Ponytail Protagonist12.002.30
Married Heroine22.002.29
Villainous Heroine12.002.27
Cunnilingus61.752.27
Sex in Water31.332.27
Bonus Side Stories21.502.26
Pissing on Others12.002.23
Private Detective Protagonist12.002.23
Discreet Phone Sex12.002.21
Shotacon12.002.21
Protagonist with Voice Acting22.002.19
Vibrators31.832.16
Nukige102.652.16
Gang Bang12.002.14
Blowjob41.422.13
Pregnancy13.002.12
Monsters12.002.11
Torture12.002.10
Sex with Sleepers12.002.09
Madness12.002.09
Suspension Bondage12.002.09
Pregnant Sex31.622.08
Protagonist's Blood-related Mother as a Heroine12.002.08
Group Sex of Multiple Females and Males13.002.06
Lesbian Sex31.672.06
Tribadism on Penis12.002.05
Anilingus21.502.04
Student Council President Heroine12.002.04
Hairjob12.002.03
Pure Love Story12.002.03
Heroine with Tights12.002.03
Read Text Marking12.002.02
Erotic Mind Control12.002.02
Defloration71.862.01
Nympho Heroine12.002.01
Betrayal12.002.00
Futanari Support Character11.401.98
Heroine with Beauty Mark12.001.98
Cats11.671.98
Duct Tape Bondage11.001.97
Student Heroine32.001.94
Sexual Corruption12.001.94
Adult Heroine22.251.93
Bathroom Sex22.001.91
Impregnation13.001.91
Sitting Sex31.671.89
Past Setting in a Fictional World12.001.88
Shy Heroine12.001.87
Scat12.001.86
Rope Bondage12.001.86
Marriage Ending12.001.86
Mind Control12.001.85
Consensual Sex Involving Slime Monsters11.001.85
Reverse Cowgirl21.501.84
Protagonist with Sexual Experience12.001.82
Perverted Protagonist12.001.81
Male on Male Sex12.001.81
Production of Pornography (Amateur)12.001.80
Plant Sex11.001.79
Heroine with Glasses22.001.79
Group Sex of One Male and Several Females41.501.78
Mentor Support Character11.001.77
Brocon Heroine12.001.77
Rapist Protagonist11.751.77
Discreet Sex12.001.76
Ponytail Heroine12.501.76
High-Tech Sex Engine11.001.72
Fisting11.001.71
Internal Exhibition of Sex12.001.71
Sexual Blindfold12.001.68
Soldier Heroine11.001.67
Female Protagonist42.381.67
High School Student Protagonist13.001.67
Heroine Having Sex with Others12.001.66
Dildos11.601.66
Energy Transfer via Sex11.001.66
Lactation During Sex21.331.65
Flashback12.001.65
High School Student Heroine32.001.65
Single Hole Multiple Tentacle Penetration (obsolete)11.001.64
Monster Birth11.251.61
Protagonist's Childhood Friend as a Heroine13.001.58
Sex at Work11.001.58
Female Domination21.001.58
Background Moans12.001.58
Erotic Spanking12.001.58
Perverted Heroine12.001.55
Spreader Bar11.001.54
Anal Toys12.001.53
Excessive Semen11.501.51
Linear Plot12.001.51
Masturbation with Object11.001.51
Teacher Heroine12.001.50
Cowgirl41.251.50
Only Virgin Heroines13.001.50
Sixty-nine21.501.49
Sexual Content42.381.49
Kinetic Novel13.001.48
Mouth Gag11.001.47
Multiple Endings32.671.47
Standing Sex21.501.46
Boobjob21.001.46
Few Choices12.001.46
Modern Day Japan12.001.45
Slime Monster Rape11.001.45
Double Dildos11.001.45
Mirror Sex11.001.41
Maid Heroine11.501.41
Cousin Incest11.001.39
Student Protagonist12.001.39
Fantasy12.001.38
Clamps (BDSM)11.001.37
Penis Growth11.001.34
High School12.001.34
Bad Ending(s)12.001.31
Blood-related Mother/Son Incest11.001.28
Single Boobjob12.001.26
Anal Sex12.001.24
Sex in a Vehicle11.001.24
Quickie Fix Position12.001.23
Lolicon11.001.20
Adult Protagonist12.251.20
Strap-on Dildos11.001.19
Twin Blowjob11.501.18
Heroine with Big Breasts21.501.16
Naked Sprites12.001.16
Double Handjob11.001.14
Protagonist with a Face22.501.14
Sex at School11.001.11
Voyeurism11.001.10
Fingering11.001.06
Handjob11.001.05
Single Blowjob12.001.05
Missionary Position12.001.04
Pissing11.001.00
Single Footjob11.000.95
Wealthy Protagonist10.500.94
Male Protagonist82.630.93
Branching Plot11.000.90
Single Handjob11.000.86
Side Portraits11.000.80
Ojousama Heroine10.670.74
ADV122.530.50
Group Sex10.170.41

Traits (439 total)

NameNovelsCharactersWeight
Bestiality Engages in (Sexual)7116.11
High-Tech Sex Engine Subject of (Sexual)355.19
Huge Insertion Subject of (Sexual)474.81
Inflated Belly Subject of (Sexual)494.70
Sex with Monsters Engages in (Sexual)274.52
Leather Bondage Subject of (Sexual)244.31
Torn Clothing Clothes364.20
Suspension Bondage Subject of (Sexual)464.11
Double-ended Dildo Subject of (Sexual)264.09
Spit-roast Subject of (Sexual)594.03
Sex in Front of an Audience Engages in (Sexual)6133.96
Gang Rape Subject of (Sexual)573.93
Garter Belt Stockings Clothes6103.88
Crotchless Panties Clothes243.87
Rope Bondage Subject of (Sexual)593.85
Double Penetration (Group Sex) Subject of (Sexual)593.80
Mary Jane Clothes253.80
Rape Subject of (Sexual)7103.76
Grotesque Stretched Nipples Subject of (Sexual)223.70
Double Handjob Engages in (Sexual)463.68
Bondage Harness Clothes243.67
Ahegao Engages in (Sexual)7153.67
Cyan Hair453.64
Thigh-high Boots Clothes353.58
Evening Gloves Clothes463.53
Scat Engages in (Sexual)243.52
Prolapse Subject of (Sexual)223.52
Doggy Style Engages in (Sexual)573.50
Wooden Horse Subject of (Sexual)233.48
Whipping (BDSM) Subject of (Sexual)243.47
Veil Clothes243.45
Trampling Subject of (Sexual)223.43
Vaginal Fisting Subject of (Sexual)333.42
Butler Role333.39
Court Shoes Clothes243.39
Multiple Penetration Subject of (Sexual)453.36
Tribadism on Penis Engages in (Sexual)243.35
Paw Gloves Clothes223.33
Bow Tie Clothes343.29
Enema Subject of (Sexual)343.25
Small Breast Sizes Body343.23
Skirt Clothes4103.21
Outdoor Sex Engages in (Sexual)7153.21
Sexual Slavery (Choukyou Variation) Subject of (Sexual)243.21
Mirror Sex Engages in (Sexual)333.20
Non-consensual Sex with Tentacles Engages in (Sexual)253.19
Duct Tape Bondage Subject of (Sexual)223.19
Chemise Clothes223.18
Rope Bondage Harness Clothes233.18
Twin Blowjob Engages in (Sexual)383.18
Anal Plug Tail Subject of (Sexual)333.17
Gynecologist Chair Subject of (Sexual)223.17
High Heeled Shoes Clothes243.14
Vaginal/Anal Sexual Toys Subject of (Sexual)353.12
Food Play Engages in (Sexual)333.09
Teal Eyes553.09
Cravat Clothes343.08
Bondage Sex Subject of (Sexual)463.07
Pissing Engages in (Sexual)473.05
Sexual Slavery (Non-consensual) Subject of (Sexual)223.04
Lesbian Sex Engages in (Sexual)383.03
Pocket Square Clothes223.02
Crown Clothes133.01
Naked in Front of an Audience Clothes122.99
Discreet Sex Engages in (Sexual)442.99
Wavy Hair682.98
Bukkake Subject of (Sexual)582.97
Reverse Spitroast Subject of (Sexual)242.97
Maid Role342.96
Itome Eyes332.95
Maid's Dress Clothes562.94
Hidden Vibrator Subject of (Sexual)332.94
Wrinkles Body332.94
Moustache Hair442.94
Standing Sex Subject of (Sexual)7112.92
Stubble Hair232.92
Maid's Headdress Clothes552.91
Masturbation Engages in (Sexual)672.91
Bathroom Sex Engages in (Sexual)372.88
Sitting Sex Subject of (Sexual)6142.88
Forehead Necklace Clothes222.87
Anilingus Subject of (Sexual)332.84
Pillory (BDSM) Subject of222.83
Dog Role222.79
Anal Beads Subject of (Sexual)232.79
Cunnilingus Subject of (Sexual)7102.79
Quickie Fix Subject of (Sexual)6122.78
Ringlet Hair232.77
Sixty-nine Engages in (Sexual)482.77
Red Eyes692.76
Turtleneck Shirt Clothes232.75
Group Sex of One Female and Several Males Engages in (Sexual)242.73
Green Eyes7132.69
Old Body332.68
Garnet Eyes442.68
Doggy Style Subject of (Sexual)9172.67
Ribbon Hair Accessory Clothes442.67
Granddaughter Role222.62
Blouse Clothes352.62
Leotard Clothes122.62
Anal Sex Subject of (Sexual)482.61
Twin Tails Hair892.60
Ribbon Tie Clothes372.60
Cardigan Clothes332.60
Thigh-high Stockings Clothes7112.60
Stuffed Toy Items222.59
Tie Pin Clothes122.58
Sexual Blindfold Subject of (Sexual)332.57
Missionary Subject of (Sexual)692.57
Puffy Sleeves Clothes332.56
Horse Role112.55
Clothing with Ribbons Clothes242.54
Spoiled Personality222.54
Clamps (BDSM) Subject of (Sexual)222.54
Housewife Role222.53
Big Breast Sizes Body242.51
Teacher Role342.50
Pissing on Others Engages in (Sexual)222.49
Hidden Eyes332.49
Infidelity Engages in332.49
Nipple Teasers Subject of (Sexual)222.49
Ribbon Hair Tie Clothes472.48
Tsurime Eyes452.48
Nipple Sucking Subject of (Sexual)452.47
Vaginal + Anal Object Insertion Subject of (Sexual)222.47
Sex in Public Places Engages in (Sexual)462.45
Bun Hair332.45
Consensual Bestiality Engages in (Sexual)112.45
Blowjob Subject of (Sexual)342.45
Female Ejaculation Engages in (Sexual)352.44
Watashi Personality262.43
White Hair352.39
Teal Hair122.37
Handcuffed Sex Subject of (Sexual)222.37
Boobs on Glass Subject of (Sexual)122.37
Gothic Clothes222.36
Object Insertion Subject of (Sexual)222.35
Shimapan Clothes222.35
Autofellatio Engages in (Sexual)112.34
Mysterious Personality332.34
Necktie Clothes472.32
Suit Clothes342.32
Livestock Subject of (Sexual)112.32
Petplay Subject of (Sexual)222.31
Hotblooded Personality122.31
Waist Length+ Hair12162.30
Slave Collar Clothes122.29
Honor Student Role222.29
Small Breasts Body332.29
Butterfly Subject of (Sexual)362.28
Blowjob Engages in (Sexual)9192.28
Blond Hair9122.28
Group Sex of One Male and Several Females Engages in (Sexual)262.28
Electrostimulator (Sexual) Subject of (Sexual)112.28
Boobs on Fence Subject of (Sexual)112.27
Glasses Clothes672.25
Noble Role222.25
Kemonomimi Headband Clothes222.25
Vaginal Fingering Subject of (Sexual)572.24
Garter Cupless Corset Clothes112.24
Mindbreak Subject of (Sexual)222.24
Cuffs Clothes222.23
Twin Bellyjob Engages in (Sexual)112.22
Boobjob Engages in (Sexual)572.22
Miniskirt Clothes472.21
Violin Items112.21
Long Hair11182.21
Hairjob Subject of (Sexual)112.21
Fishnet Garter Belt Stockings Clothes112.20
Classmate Role252.20
Shinai Items112.20
Princess Role222.19
Beret Clothes122.19
Virgin Sex Engages in (Sexual)8122.19
Sex with Others Engages in (Sexual)122.19
Queen Consort Role112.17
Sex in Water Engages in (Sexual)332.17
Facesitting Engages in (Sexual)122.17
Vibrator Subject of (Sexual)222.16
Selfish Personality222.15
Sidehair Hair782.15
Vaginal Gaping Engages in (Sexual)222.14
Ojousama Role222.14
Scar Body222.14
Ponytail Hair562.14
Cosplay Engages in222.12
Vest Clothes232.11
Pendant Necklace Clothes232.11
Masturbation with Water Engages in (Sexual)112.11
Plate Armor Clothes222.10
Medium Breasts Body232.09
Villain Role222.09
Beard Hair222.08
Choker Clothes332.08
Necklace Clothes332.08
Straight Hair682.07
Shirt Clothes452.07
Spiky Bangs Hair572.07
Bonnet Clothes112.07
Naked Apron Clothes222.06
Rhythmic Gymnastics Engages in112.06
Green Hair332.05
Parted to Side Hair462.04
Seventh Posture Subject of (Sexual)332.03
Pendant Earrings Clothes222.02
Dress Clothes442.02
Brown Hair10182.02
Younger Sister Role332.00
String Ribbon Tie Clothes222.00
Violinist Role112.00
Rape Engages in (Sexual)221.99
Hair Ribbon Clothes221.98
Husband Role221.97
Lab Coat Clothes221.97
Rapier Items111.96
High School Student Role491.96
Braid Hair221.96
Mullet Hair111.96
Autobukkake Subject of (Sexual)111.95
Blunt Bangs Hair331.94
Anal Sex Engages in (Sexual)221.94
Reverse Rape Subject of (Sexual)111.93
Blue Eyes8101.93
Handjob Subject of (Sexual)121.93
Pajamas Clothes221.92
Side Tail Hair121.92
Vaginal Multiple Tentacle Penetration Subject of (Sexual)111.92
Grey Hair231.92
Skirt Suit Clothes221.91
Discreet Masturbation Engages in (Sexual)111.91
Shoulder-length Hair471.91
Older Brother Role221.90
PE Teacher Role111.90
Tentacle Rape Engages in (Sexual)111.89
Cape Clothes121.88
Tominagi Subject of (Sexual)331.88
Brown Eyes571.87
Stoic Personality221.87
Arrogant Personality121.86
Handjob Engages in (Sexual)341.86
Anal Masturbation Engages in (Sexual)111.86
Central Heterochromia Eyes111.85
Teen Body6191.85
Amber Eyes451.85
Carefree Personality221.85
Pink Hair331.84
Seduction Subject of111.84
Boots Clothes221.84
Vaginal Masturbation Engages in (Sexual)221.84
Humping Engages in (Sexual)111.83
Slim Body6231.83
Collar Clothes221.83
Cyan Eyes121.83
Pet Role111.82
Wealthy Role221.82
Title Character Role111.81
Tailcoat Clothes111.81
Pubic Hair Shaving Subject of (Sexual)111.81
Public Use (Choukyou or Non-Consensual) Subject of (Sexual)111.81
Curtained Hair231.80
Spear Items111.80
Sweater Clothes221.79
Reverse Cowgirl Subject of (Sexual)221.79
Bondage Engages in111.77
Monster Role111.76
Speculum (Sexual) Subject of (Sexual)111.76
Forced Public Nudity Subject of (Sexual)111.76
Lactation Engages in221.75
Slavery Subject of111.75
Whip Items111.74
King Role111.74
Sleep Sex Subject of (Sexual)111.73
Leather Jacket Clothes111.73
Wake-up Sex Subject of (Sexual)111.72
Secretary Role111.72
Consensual Group Sex of One Female and Several Males Engages in (Sexual)111.72
Bow Items111.72
Trench Coat Clothes111.71
Bracelet Clothes221.71
Cowgirl Subject of (Sexual)451.71
School Nurse Role111.71
Homeroom Teacher Role111.70
Tentacle Restraint Subject of111.70
Casual Sex Engages in (Sexual)111.70
Masturbation with Object Engages in (Sexual)111.70
Discreet Phone Sex Engages in (Sexual)111.70
Sports Engages in111.69
Prince Role111.69
Monster Birth Engages in111.69
Baby-doll Clothes111.69
Violet Eyes341.69
Group Sex Engages in (Sexual)121.67
Orange Hair221.66
Torture Engages in111.66
Blue Hair331.66
Sports Bra Clothes111.65
Non-consensual Porn Acting Subject of (Sexual)111.65
Short Hair7141.64
Cupless Corset Clothes111.64
Vaginal + Anal Tentacle Penetration Subject of (Sexual)111.64
Student Role221.64
Confinement Engages in111.64
Serious Personality121.64
Non-Humanoid Body111.63
Hairjob Engages in (Sexual)111.62
Servant Role111.62
Penis Growth Subject of111.62
Jitome Eyes111.62
Tracksuit Clothes111.61
Twin Blowjob Subject of (Sexual)111.60
Transparent Clothes111.60
Tiara Clothes111.59
Handbag Items111.59
Nightgown Clothes111.58
Infidelity Subject of111.58
Intercrural Sex Subject of (Sexual)111.58
School Uniform Clothes471.57
Black Hair461.57
Pantyhose Clothes221.57
Name Tag Clothes111.57
Big Breasts Body331.56
Jacket Clothes121.56
Secret Identity Role111.55
V Bangs Hair221.55
Hair Tie Clothes121.55
Hairpin Clothes221.54
Brooch Clothes111.54
Public Masturbation Engages in (Sexual)111.53
Detective Role111.53
Spats Clothes111.53
Knee-high Socks Clothes221.52
Seventh Posture Engages in (Sexual)111.52
Seduction Engages in111.51
Pet Owner Role111.51
Closet Pervert Personality111.50
Mind Control Subject of111.50
Torture Subject of111.50
Nurse Role111.49
Sexual Sadism Engages in (Sexual)111.49
Armband Clothes111.49
Executive Role111.49
Fainting Subject of111.48
Vindictive Personality111.48
Mouth Gag Subject of (Sexual)111.48
Management Role111.47
Flustered Personality111.47
Knight Role111.47
Red Hair221.45
Nurse's Cap Clothes111.45
Medical Doctor Role111.44
T-shirt Clothes221.44
Student Council President Role111.44
Brother Complex Personality111.43
Being Drugged Subject of111.43
Bullying Subject of111.43
Corset Clothes111.42
Bracer Clothes111.42
Cross Necklace Clothes111.42
Docile Personality111.42
Cloak Clothes111.42
Turtleneck Sweater Clothes111.41
Sex on Toilet Engages in (Sexual)111.41
Hime Cut Hair111.40
Towel Clothes111.40
Nurse Uniform Clothes111.39
Spaulders Clothes111.39
Wedding Ring Clothes111.39
Cleaning Engages in111.38
Overweight Body111.38
Parted in Middle Hair221.37
Sexual Corruption Subject of111.36
Naked Clothes111.36
Taciturn Personality111.35
Strange Personality111.35
Ring Clothes111.34
Cruel Personality111.34
Masturbation in front of an Audience Engages in (Sexual)111.32
Atashi Personality111.32
Younger Brother Role111.32
Tanned Body111.32
Violet Hair221.32
Quickie Fix Engages in (Sexual)111.30
Trousers Clothes221.30
Fang Body111.30
Tsundere Personality111.30
Timid Personality111.29
Boyfriend Role111.29
Fingerless Gloves Clothes111.29
Intercrural Sex Engages in (Sexual)111.28
Strict Personality111.27
Knee-high Boots Clothes111.27
Blazer Clothes111.27
Detached Sleeves Clothes111.26
Son Role111.26
Hair Flower Clothes111.23
Confinement Subject of111.22
Short Shorts Clothes111.21
Missionary Engages in (Sexual)111.21
Pale Body7251.20
Footjob Engages in (Sexual)111.19
Sport Bloomers Clothes111.19
Coat Clothes111.18
Hoodie Clothes111.18
Nipple Sucking Engages in (Sexual)111.18
Naive Personality111.17
Intake Hair111.16
Stubborn Personality111.16
Father Role111.16
No Bangs Hair111.14
Pointed Ears Body111.14
Popular Role111.13
Kouhai Role111.13
Pervert Personality111.13
Kind Personality121.13
Vaginal Fingering Engages in (Sexual)111.12
Apron Clothes111.10
Mole Body111.09
Kimono Clothes111.09
Nipple Teasing Subject of (Sexual)111.09
Full Sister Role111.08
Cunnilingus Engages in (Sexual)111.07
Sex at School Engages in (Sexual)111.07
Sex while Being Pregnant Engages in (Sexual)111.06
Wife Role111.06
Energetic Personality111.05
Young-adult Body331.05
Mother Role111.01
Headband Clothes111.01
Earrings Clothes110.99
Cooking Engages in110.98
Not a Virgin Role110.98
Gloves Clothes110.98
Tank Top Clothes110.98
Pregnancy Subject of110.97
Pubic Hair Hair110.93
Ahoge Hair110.92
Fighting Engages in110.90
Friendly Personality110.84
Friend Role110.83
Data provided by VNDB under the terms of the Open Database License